Aerosol generation device, control method and storage medium

ABSTRACT

An aerosol generation device includes: a load configured to heat an aerosol generation article including an aerosol-forming substrate configured to hold or carry at least one of an aerosol source and a flavor source; and a controller configured to control power that is supplied from a power source to the load. When a phase where a temperature of the load is equal to or higher than a value at which a predetermined amount or more of aerosols is capable of being generated from the aerosol generation article, the controller is configured to acquire the temperature of the load and a degree of progress of the phase, to execute feedback control so that the temperature of the load converges to a predetermined temperature, and to increase a gain in the feedback control or an upper limit value of the power, as the degree of progress progresses, in the feedback control.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of PCT application No.PCT/JP2018/012243, which was filed on Mar. 26, 2018, the contents ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an aerosol generation device, a controlmethod and a storage medium.

BACKGROUND

For example, an aerosol generation device configured to heat an aerosolgeneration article by an electric heating element such as an electricheater, and to generate aerosols is used.

The aerosol generation device includes an electric heating element and acontrol unit configured to control the electric heating element itselfor power that is supplied to the electric heating element. The aerosolgeneration device is mounted with an aerosol generation article such asa stick or pod including cigarette formed into a sheet or particleshape, for example. The aerosol generation article is heated by theelectric heating element, so that aerosols are generated.

As a heating method of the aerosol generation article, there are threefollowing heating methods, for example.

In a first heating method, a rod-shaped electric heating element isinserted into the aerosol generation article, and the electric heatingelement inserted into the aerosol generation article heats the aerosolgeneration article. Japanese Patent Nos. 6,046,231, 6,125,008 and6,062,457 and the like disclose control technologies on the heating bythe first heating method, for example.

In a second heating method, an annular electric heating element coaxialwith the aerosol generation article is arranged on an outer peripheralpart of the aerosol generation article, and the electric heating elementheats the aerosol generation article from an outer periphery-side of theaerosol generation article.

In a third heating method, a metal piece (also referred to as‘susceptor’) that generates heat by eddy current generated therein by amagnetic field penetrating the metal piece is inserted in advance in theaerosol generation article. Then, the aerosol generation article ismounted to an aerosol generation device having a coil, AC current isenabled to flow through the coil to generate a magnetic field, and themetal piece in the aerosol generation article mounted to the aerosolgeneration device is heated using an induction heating (IH) phenomenon.

For example, it is preferable that a time period from start of heatinguntil a user can inhale aerosols is short in the aerosol generationdevice, from a standpoint of convenience of the aerosol generationdevice. Also, from a standpoint of a quality of the aerosol generationdevice, it is preferable to stabilize an amount of generation ofaerosols after the user can inhale aerosols until the heating is over,thereby stabilizing flavor and taste that are given to the user.

The present invention has been made in view of the above situations, andis to provide an aerosol generation device, a control method and astorage medium capable of appropriately heating an aerosol generationarticle to thereby stabilize an amount of aerosol generation.

SUMMARY

An aerosol generation device relating to a first example includes: aload configured to heat an aerosol generation article by using powerthat is supplied from a power source, the aerosol generation articleincluding an aerosol-forming substrate configured to hold or carry atleast one of an aerosol source and a flavor source; and a control unitconfigured to control the power that is supplied from the power sourceto the load. In a case of a use phase where a temperature of the load isequal to or higher than a value at which a predetermined amount or moreof aerosols is capable of being generated from the aerosol generationarticle, the control unit is configured to acquire the temperature ofthe load and a degree of progress of the use phase, to execute feedbackcontrol so that the temperature of the load converges to a predeterminedtemperature, and to increase a gain in the feedback control or an upperlimit value of the power that is supplied from the power source to theload, as the degree of progress progresses, in the feedback control.

A control method relating a second example is a control method of powerthat is supplied from a power source to a load, in which the load isused to heat an aerosol generation article including an aerosol-formingsubstrate configured to hold or carry at least one of an aerosol sourceand a flavor source. The control method includes: starting supply of thepower from the power source to the load; in a case of a use phase wherea temperature of the load is equal to or higher than a value at which apredetermined amount or more of aerosols is capable of being generatedfrom the aerosol generation article, acquiring the temperature of theload and a degree of progress of the use phase; executing feedbackcontrol so that the temperature of the load converges to a predeterminedtemperature; and increasing a gain in the feedback control or an upperlimit value of the power that is supplied from the power source to theload, as the degree of progress progresses, in the feedback control.

An aerosol generation device relating to a third example includes: aload configured to heat an aerosol generation article by using powerthat is supplied from a power source, the aerosol generation articleincluding an aerosol-forming substrate configured to hold or carry atleast one of an aerosol source and a flavor source; and a control unitconfigured to acquire a temperature of the load, to execute feedbackcontrol, based on the temperature of the load, and to control the powerthat is supplied from the power source to the load. The control unit isconfigured to increase a gain in the feedback control or an upper limitvalue of the power that is supplied from the power source to the load sothat the temperature of the load gradually approaches from a firsttemperature, at which a predetermined amount or more of aerosols iscapable of being generated from the aerosol source or theaerosol-forming substrate included in the aerosol generation article andlocated in a position closest to the load, to a second temperature atwhich the predetermined amount or more of aerosols is capable of beinggenerated from the aerosol source or the aerosol-forming substrateincluded in the aerosol generation article and located in a positionmost distant from the load.

A control method relating to a fourth example is a control method ofpower that is supplied from a power source to a load, in which the loadis used to heat an aerosol generation article including anaerosol-forming substrate configured to hold or carry at least one of anaerosol source and a flavor source. The control method includes:starting supply of the power from the power source to the load;acquiring a temperature of the load; executing feedback control, basedon the temperature of the load to control the power that is suppliedfrom the power source to the load; and increasing a gain in the feedbackcontrol or an upper limit value of the power that is supplied from thepower source to the load so that the temperature of the load graduallyapproaches from a first temperature, at which a predetermined amount ormore of aerosols is capable of being generated from the aerosol sourceor the aerosol-forming substrate included in the aerosol generationarticle and located in a position closest to the load, to a secondtemperature at which the predetermined amount or more of aerosols iscapable of being generated from the aerosol source or theaerosol-forming substrate included in the aerosol generation article andlocated in a position most distant from the load.

An aerosol generation device relating to a fifth example includes: aload configured to heat an aerosol generation article by using powerthat is supplied from a power source, the aerosol generation articleincluding an aerosol-forming substrate configured to hold or carry atleast one of an aerosol source and a flavor source; and a control unitconfigured to control the power that is supplied from the power sourceto the load. In a case of a use phase where a temperature of the load isequal to or higher than a value at which a predetermined amount or moreof aerosols is capable of being generated from the aerosol generationarticle, the control unit is configured to acquire the temperature ofthe load and a degree of progress of the use phase, to determine thepower that is supplied from the power source to the load, based on adifference between the temperature of the load and a predeterminedtemperature, and to execute feedback control so that a change rate of asupply amount of the power along with progressing of the use phase isgreater than a change rate of the predetermined temperature with theprogressing of the use phase.

A control method relating to a sixth example is a control method ofpower that is supplied from a power source to a load, in which the loadis used to heat an aerosol generation article including anaerosol-forming substrate configured to hold or carry at least one of anaerosol source and a flavor source. The control method includes:starting supply of the power from the power source to the load; in acase of a use phase where a temperature of the load is equal to orhigher than a value at which a predetermined amount or more of aerosolsis capable of being generated from the aerosol generation article,acquiring the temperature of the load and a degree of progress of theuse phase; and determining the power that is supplied from the powersource to the load, based on a difference between the temperature of theload and a predetermined temperature, and executing feedback control sothat a change rate of a supply amount of the power with progressing ofthe use phase is greater than a change rate of the predeterminedtemperature with the progressing of the use phase.

An aerosol generation device relating to a second example includes: aload configured to heat an aerosol generation article by using powerthat is supplied from a power source, the aerosol generation articleincluding an aerosol-forming substrate configured to hold or carry atleast one of an aerosol source and a flavor source; and a control unitconfigured to control the power that is supplied from the power sourceto the load. In a case of a use phase where a temperature of the load isequal to or higher than a value at which a predetermined amount or moreof aerosols is capable of being generated from the aerosol generationarticle, the control unit is configured to acquire the temperature ofthe load and a degree of progress of the use phase, to determine thepower that is supplied from the power source to the load, based on adifference between the temperature of the load and a predeterminedtemperature, and to execute feedback control so that a value obtained bysubtracting the temperature of the load from the predeterminedtemperature decreases along with progressing of the use phase and asupply amount of the power that is supplied from the power source to theload increases with the progressing of the use phase.

A control method relating to an eighth example is a control method ofpower that is supplied from a power source to a load, in which the loadis used to heat an aerosol generation article including anaerosol-forming substrate configured to hold or carry at least one of anaerosol source and a flavor source. The control method includes:starting supply of the power from the power source to the load; in acase of a use phase where a temperature of the load is equal to orhigher than a value at which a predetermined amount or more of aerosolsis capable of being generated from the aerosol generation article,acquiring the temperature of the load and a degree of progress of theuse phase; and determining the power that is supplied from the powersource to the load, based on a difference between the temperature of theload and a predetermined temperature, and executing feedback control sothat a value obtained by subtracting the temperature of the load fromthe predetermined temperature decreases with progressing of the usephase and a supply amount of the power that is supplied from the powersource to the load increases with the progressing of the use phase.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram depicting an example of a basic configurationof an aerosol generation device in accordance with an embodiment;

FIG. 2 is a graph depicting an example of changes in power that issupplied to a load by control in accordance with the embodiment and intemperature of the load;

FIG. 3 is a control block diagram depicting an example of control thatis executed by a control unit of the aerosol generation device inaccordance with the embodiment;

FIG. 4 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 1A;

FIG. 5 is a flowchart depicting an example of processing in apreparation phase by the control unit in accordance with Example 1A;

FIG. 6 is a graph depicting an example of a state in which a temperatureof the load is uneven between the preparation phase and a use phase;

FIG. 7 is a graph depicting an example of control on a duty ratio in afirst sub-phase;

FIG. 8 is a flowchart depicting an example of processing in thepreparation phase by the control unit in accordance with Example 1B;

FIG. 9 depicts an example of a relation between current that flows froma power source to a load and a voltage that is applied to the load bythe power source;

FIG. 10 is a graph depicting an example of relations of a full-chargedvoltage, a discharge-end voltage, a current corresponding to thefull-charged voltage and a current corresponding to the discharge-endvoltage in the first sub-phase of the preparation phase;

FIG. 11 is a graph depicting an example of comparison between a changein temperature of the load in the preparation phase when a voltage ofthe power source is a full-charged voltage at the start of the firstsub-phase and a change in temperature of the load in the preparationphase when a voltage of the power source is near the discharge-endvoltage at the start of the first sub-phase, in a case where a dutyratio is constant;

FIG. 12 is a graph exemplifying a relation between the full-chargedvoltage and the discharge-end voltage implemented by PWM control and arelation between a current corresponding to the full-charged voltage anda current corresponding to the discharge-end voltage;

FIG. 13 is a flowchart depicting an example of processing in thepreparation phase by the control unit in accordance with Example 1C;

FIG. 14 is a graph depicting an example of control that is executed bythe control unit in accordance with Example 1D;

FIG. 15 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 1D;

FIG. 16 is a flowchart depicting an example of processing in thepreparation phase by the control unit in accordance with Example 1D;

FIG. 17 is a flowchart depicting an example of processing in thepreparation phase by the control unit in accordance with Example 1E;

FIG. 18 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 2A;

FIG. 19 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 2A;

FIG. 20 is a control block diagram depicting an example of changing alimiter width in a limiter change unit in accordance with Example 2B;

FIG. 21 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 2B;

FIG. 22 is a graph depicting an example of a change in limiter widththat is used in the limiter unit and a state of increase in temperatureof the load;

FIG. 23 is a graph depicting an example of a change in the limiter widthin accordance with Example 2C;

FIG. 24 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 2D;

FIG. 25 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 2D;

FIG. 26 is a flowchart depicting an example of the use phase by thecontrol unit in accordance with Example 2E;

FIG. 27 is a graph depicting an example of comparison between a usephase end temperature in accordance with a second embodiment and atarget temperature in accordance with an aerosol generation device ofthe related art;

FIG. 28 is a graph depicting an example of comparison of a differencebetween the use phase end temperature and a measured temperature valuein accordance with the second embodiment and a difference between thetarget temperature and a measured temperature value in accordance withthe aerosol generation device of the related art;

FIG. 29 is a table showing comparison of the preparation phase and theuse phase that are executed by the control unit in accordance with athird embodiment;

FIG. 30 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 4A;

FIG. 31 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 4A;

FIG. 32 is a graph depicting an example of a generation state ofovershoot in the temperature of the load 3;

FIG. 33 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 4B;

FIG. 34 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 4B;

FIG. 35 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 4C;

FIG. 36 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 4C;

FIG. 37 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 4D;

FIG. 38 is a flowchart depicting an example of processing in anovershoot detection unit in accordance with Example 4D;

FIG. 39 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 4E;

FIG. 40 is a flowchart depicting an example of processing in thepreparation phase by the control unit in accordance with Example 4E;

FIG. 41 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 4E;

FIG. 42 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 5A;

FIG. 43 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 5A;

FIG. 44 is a graph depicting an example of changes in the temperature ofthe load 3 and the limiter width;

FIG. 45 depicts an example of a limiter change unit in accordance withExample 5B;

FIG. 46 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 5B;

FIG. 47 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 5C;

FIG. 48 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 5C;

FIG. 49 is a control block diagram depicting an example of control thatis executed by the control unit in accordance with Example 5D;

FIG. 50 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 5D;

FIG. 51 is a graph depicting an example of changes in the temperature ofthe load and the limiter width in accordance with Example 5E; and

FIG. 52 is a flowchart depicting an example of processing in the usephase by the control unit in accordance with Example 5E.

DESCRIPTION OF EMBODIMENTS

Hereinbelow, the present embodiment will be described with reference tothe drawings.

In descriptions below, the functions and constitutional elements thatare omitted or substantially the same are denoted with the samereference signs, and are described only when necessary.

An aerosol generation device of the present embodiment is described bytaking, as an example, an aerosol generation device for an aerosolgeneration article (solid heating), for example. However, the aerosolgeneration device of the present embodiment may also be an aerosolgeneration device of another type or usage, such as a medical nebulizer(spraying device), for example.

The aerosol generation device of the present embodiment is described bytaking, as an example, a case where aerosols are generated using thefirst heating method of heating the aerosol generation article from aninside thereof by using an electric heating element inserted into theaerosol generation article. However, the aerosol generation device ofthe present embodiment may also use another heating method such as thesecond heating method of heating the aerosol generation article from anoutside thereof by using an annular electric healing element arranged onan outer peripheral part of the aerosol generation article or the thirdheating method of heating the aerosol generation article from an insidethereof by using an induction heating phenomenon.

FIG. 1 is a block diagram depicting an example of a basic configurationof an aerosol generation device 1 in accordance with the embodiment.

The aerosol generation device 1 includes a mounting unit 2, a load 3, apower source 4, a timer 5, a temperature measurement unit 6, a powersource measurement unit 7, and a control unit 8.

The mounting unit 2 is configured to detachably support an aerosolgeneration article 9.

The aerosol generation article 9 includes an aerosol-forming substrate 9a configured to hold or carry at least one of an aerosol source and aflavor source, for example. The aerosol generation article 9 may be asmoking article, for example, and may be formed into a shape such as astick shape that is easy to use, for example.

The aerosol source may be liquid or solid including polyhydric alcoholsuch as glycerin or propylene glycol, for example. Also, the aerosolsource may further contain a nicotine component, for example, inaddition to polyhydric alcohol.

The aerosol-forming substrate 9 a is a solid material in which theaerosol source is added or carried, for example, and may be a cigarettesheet, for example.

The aerosol-forming substrate 9 a may be a substrate that can emit avolatile compound capable of generating aerosols so that the substratefunctions as the aerosol source or the flavor source, for example. Thevolatile compound is emitted by heating the aerosol-forming substrate 9a. In the present embodiment, the aerosol-forming substrate 9 a is apart of the aerosol generation article 9.

The load 3 is, for example, an electric heating element, and isconfigured to generate heat as power is supplied from the power source4, thereby heating the aerosol generation article 9 mounted to themounting unit 2.

The power source 4 is a battery or a battery pack in which a battery, afield emission transistor (FET), an FET for discharge, a protection IC(Integrated Circuit), a monitoring device and the like are combined, andis configured to supply power to the load 3. The power source 4 is achargeable secondary battery, and may be a lithium-ion secondarybattery, for example. The power source 4 may be included in the aerosolgeneration device 1 or may be configured separately from the aerosolgeneration device 1.

The timer 5 is configured to output, to the control unit 8, a timervalue t indicating a time since the power is supplied to the load 3 in anon-operation state.

Herein, the non-operation state may be a state in which the power source4 is off or a state in which the power source 4 is on but is not waitingfor the supply of power to the load 3. The non-operation state may alsobe a standby state.

In the meantime, the timer value may also indicate a time counted fromstart of aerosol generation, a time from start of heating of the load 3,or a time from start of control by the control unit 8 of the aerosolgeneration device 1.

The temperature measurement unit 6 is configured to measure atemperature of the load 3 (heater temperature), for example, and tooutput the measured temperature value to the control unit 8. In themeantime, a heater having a positive temperature coefficient (PTC)characteristic that a resistance value changes in accordance with atemperature may be used for the load 3. In this case, the temperaturemeasurement unit 6 may be configured to measure an electric resistancevalue of the load 3, and to derive a temperature of the load 3 (heatertemperature) from the measured electric resistance value.

The power source measurement unit 7 is configured to measure a powersource state value indicative of a state of the power source 4 such as avalue relating to a remaining amount of the power source 4, a voltagevalue that is output by the power source 4 or a current that isdischarged from the power source 4 or a current that is charged in thepower source 4, and to output the power source state value to thecontrol unit 8.

Herein, as the value relating to the remaining amount of the powersource 4, for example, an output voltage of the power source 4 may beused. Alternatively, a state of charge (SOC) of the power source 4 maybe used. The SOC may be estimated from a voltage or current measured bya sensor by using an open circuit voltage (SOC-OCV) method or a currentintegration method (Coulomb counting method) of integrating charging anddischarging currents of the power source 4.

The control unit 8 is configured to control power that is supplied fromthe power source 4 to the load 3, based on the timer value input fromthe timer 5 and the measured temperature value input from thetemperature measurement unit 6, for example. Also, the control unit 8may be configured to execute the control by using the power source statevalue input from the power source measurement unit 7, for example. Thecontrol unit 8 includes a computer, a controller or a processor and amemory, and the computer, controller or processor may be configured toexecute a program stored in the memory to execute the control, forexample.

FIG. 2 is a graph depicting an example of changes in power that issupplied to the load 3 by control in accordance with the presentembodiment and in temperature of the load 3, In FIG. 2 , the horizontalaxis indicates the tinier value t, i.e., time, and the vertical axisindicates the power that is supplied to the load 3 and the temperatureof the load 3.

The control unit 8 is configured to mainly switch the control between apreparation phase and a use phase.

For example, in the preparation phase, a state in which the load 3cannot generate a predetermined amount or more of aerosols from theaerosol generation article 9 is referred to as a preparation state. Thepreparation state may also be a state after heating of the load 3 startsin response to receiving a user's input until the user is allowed toinhale (puff) aerosols with the aerosol generation device 1, forexample. In other words, in the preparation state, it is assumed thatthe user is not allowed to inhale aerosols with the aerosol generationdevice 1.

The predetermined amount corresponds to an amount of aerosol generationat which the user is allowed to inhale aerosols, for example.

More specifically, the predetermined amount may be an amount at which aneffective amount of aerosols can be delivered into a user's mouth, forexample. As used herein, the effective amount may be an amount at whichthe user can be given with flavor and taste originating from the aerosolsource or the flavor source included in the aerosol generation article.The predetermined amount may also be an amount of aerosols that aregenerated by the load 3 and can be delivered into the user's mouth, forexample. The predetermined amount may also be an amount of aerosols thatare generated when the temperature of the load 3 is equal to or higherthan a boiling point of the aerosol source, for example. Thepredetermined amount may also be an amount of aerosols that aregenerated from the aerosol generation article 9 when the power suppliedto the load 3 is equal to or higher than power that should be suppliedto the load 3 so as to generate aerosols from the aerosol generationarticle 9, for example. In the preparation state, the load 3 may notgenerate aerosols from the aerosol generation article 9, i.e., thepredetermined amount may be zero.

When starting the supply of power to the load 3 in the non-operationstate or when the load 3 is in the preparation state, the control unit 8may control the power that is supplied from the power source 4 to theload 3 by feed-forward control (ET control).

When the load 3 shifts from the preparation state to a use state, thecontrol unit 8 may execute feedback control (F/B control) or both thefeedback control and the feed-forward control.

For example, in the use phase, a state in which the load 3 can generatethe predetermined amount or more of aerosols from the aerosol generationarticle 9 is referred to as a use state. The use state may also be astate after the user is allowed to inhale aerosols until the aerosolgeneration is over, for example.

The control that is executed by the control unit 8 will be specificallydescribed in first to fifth embodiments to be described later.

A dotted line L₁ indicates a state in which the power supplied to theload 3 changes in accordance with the timer value t. For example, thecontrol unit 8 may control the power that is supplied from the powersource 4 to the load 3 by pulse width modulation (PWM) control or pulsefrequency modulation (PFM) control on a switch not shown in FIG. 1 .Alternatively, the control unit 8 may control the power that is suppliedfrom the power source 4 to the load 3 by stepping up or stepping downthe output voltage of the power source 4 by a DC/DC converter not shownin FIG. 1 . In the preparation phase in which the load 3 is in thepreparation state, high power is supplied from the power source 4 to theload 3, and then the power that is supplied from the power source 4 tothe load 3 is lowered. When the load 3 shifts from the preparation phaseto the use phase in which the load is in the use state, the power thatis supplied from the power source 4 to the load 3 stepwise increases asthe timer value t increases. Then, when an end condition of the usestate of the load 3 is satisfied, for example, when the temperature ofthe load 3 reaches a use phase end temperature or when the timer value tis a threshold value or larger indicative of an end of the use phase,the supply of power to the load 3 is stopped.

A solid line L₂ indicates a state in which the temperature of the load 3changes in accordance with the timer value t. In the preparation phase,the temperature of the load 3 rapidly increases while the high power issupplied from the power source 4 to the load 3. After the power that issupplied from the power source 4 to the load 3 in the preparation phaseis lowered, the temperature of the load 3 is kept or slightly increases.When the shift to the use phase is made, the power that is supplied fromthe power source 4 to the load 3 stepwise increases over time, and thetemperature of the load 3 also gradually increases. The control unit 8executes the feedback control on the basis of the measured temperaturevalue input from the temperature measurement unit 6 so that thetemperature of the load 3 is to be the use phase end temperature at theend of the use phase.

The use phase end temperature is a temperature of the load 3 that is setso as to finally converge or reach in the feedback control. The feedbackcontrol of the present embodiment controls the supply of power to theload 3 so that there is no difference between the use phase endtemperature and the measured temperature value at the end of the usephase.

FIG. 3 is a control block diagram depicting an example of control thatis executed by the control unit 8 of the aerosol generation device 1 ofthe present embodiment.

The control unit 8 includes a preparation unit 10, a differential unit11, a gain unit 12, a limiter change (adjusting) unit 13, a limiter unit14, and a comparison unit 15. The constitutional elements of the controlunit 8 will be specifically described later, respectively.

The control that is executed by the control unit 8 has mainly first tofifth features. The power that is supplied from the power source 4 tothe load 3 is controlled by the control unit 8, so that it is possibleto shorten a time of the preparation phase and to stabilize the amountof aerosol generation in the use phase.

The control unit 8 has a first feature of executing the feed-forwardcontrol in the preparation phase.

The control unit 8 has a second feature of expanding a limiter width ofthe limiter unit 14 in the feedback control in the use phase.

The control unit 8 has a third feature of using different control modesbetween the preparation phase and the use phase.

The control unit 8 has a fourth feature of suppressing decrease intemperature of the load 3 upon shift from the preparation phase to theuse phase.

The control unit 8 has a fifth feature of recovering decrease intemperature when the user inhales aerosols in the use phase.

The aerosol generation device 1 of the present embodiment is configuredto heat the aerosol generation article 9 by the load 3, for example,thereby generating aerosols from the aerosol generation article 9. Thecontrol unit 8 is configured to control the supply of power to the load3 so that aerosols generated during the heating of the load 3 do notlargely vary.

In order to implement the stable aerosol generation in one control modeor one control phase, it is necessary to change control parameters suchas a target temperature over time, so that it may be difficult toperform the stable control.

In contrast, the control unit 8 of the present embodiment divides anduses the plurality of different control modes, specifically, thefeed-forward control and the feedback control for heating of the load 3,thereby enabling the stable aerosol generation.

In the first to fifth embodiments to be described later, the firstfeature to the fifth feature will be specifically described.

In the present embodiment and the first to fifth embodiments, as anexample, the feed-forward control and the feedback control may beconfigured as different control modes. The feed-forward control may be acontrol in which an operating amount of an operation target is notdetermined based on a control amount of a control target. In otherwords, the feed-forward control may be a control in which a controlamount of a control target is not used as a feedback component, forexample. As another example, the feed-forward control may also be acontrol in which a control amount of a control target is determinedbased on only a predetermined algorithm or variable or based on acombination of the predetermined algorithm or variable and any physicalquantity acquired before outputting a control command relating to theoperating amount to an operation target. The feedback control may be acontrol in which an operating amount of an operation target isdetermined based on a control amount of a control target, for example.In other words, the feedback control may be a control in which a controlamount of a control target is used as a feedback component, for example.As another example, the feedback control may also be a control in whichan operating amount of an operation target is determined based on acombination of any physical quantity acquired during execution of thecontrol, in addition to a predetermined algorithm or variable.

In the first to third embodiments, the term “overheat” means a state inwhich a temperature of a control target is slightly higher than atemperature to be controlled (for example, the use phase end temperatureor the target temperature). That is, it should be noted that it does notnecessarily mean that the control target is in an excessivelyhigh-temperature state.

First Embodiment

In the first embodiment, the feed-forward control in the preparationphase is described.

The control unit 8 of the first embodiment controls the power that issupplied from the power source 4 to the load 3 by the feed-forwardcontrol when starting the supply of power to the load 3 in thenon-operation state or when the load 3 is in the preparation state inwhich the load 3 cannot generate a predetermined amount or more ofaerosols from an aerosol generation article. In this way, thetemperature of the load 3 in the preparation state is increased by thefeed-forward control, so that it is possible to speed up the increase intemperature of the load 3 until the load is in the use state.

The control unit 8 is configured to execute the feed-forward control soas to supply the load 3 with an amount of power necessary for the load 3to shift from the non-operation state or the preparation state to theuse state. In this way, the temperature of the load 3 is increased tothe use state by the feed-forward control, so that it is possible toshorten a time necessary for the load 3 to be in the use state.

Herein, it is specifically described that the control unit 8 executesthe feed-forward control so as to shorten a time until the load 3 is inthe use state. For example, when the control unit 8 executes thefeedback control to shift the load 3 in the non-operation state or inthe preparation state to the use state, a control amount affectsdetermination of an operating amount. Therefore, a time necessary forthe load 3 to be in the use state is likely to lengthen. Particularly,in an aspect where the load 3 is subjected to the use state from arelatively early stage of the preparation phase by the feedback control,when a gain (transfer function) is small, a rate of temperature increaseof the load 3 is slowed down, and when the gain is large, the load 3 isdifficult to converge to the use state. Also, in an aspect where atarget temperature of the load 3 is gradually increased over time by thefeedback control in the preparation phase, when the measured temperaturevalue of the load 3 reverses the target temperature, stagnation intemperature increase may occur. In contrast, when the control unit 8executes the feed-forward control in the preparation phase, the concern,which occurs when the feedback control is used in the preparation phaseas described above, does not occur. Therefore, it is possible to shortenthe time until the load 3 is in the use state. For this reason,regarding the control that is executed by the control unit 8 so as toshift the load 3 in the non-operation state or in the preparation stateto the use state, it can be said that the feed-forward control is morepreferable than the feedback control.

The control unit 8 may be configured to execute the feed-forward controlso as to suppress the power that is supplied from the power source 4 tothe load 3, after supplying the necessary amount of power to the load 3.In this case, in order to suppress the power, for example, the powerthat is supplied to the load 3 so as to keep the temperature of the load3 may be suppressed. In this way, after supplying the necessary amountof power to the load 3, the power that is supplied from the power source4 to the load 3 is suppressed, so that the aerosol generation device 1and the aerosol generation article 9 can be prevented from beingoverheated. In the meantime, if the aerosol generation device 1 is putin an overheated state, the lifetimes of the power source 4, the controlunit 8, the load 3, a circuit for electrically connecting the powersource 4 and the load 3, and the like of the aerosol generation device 1may be reduced. Also, if the aerosol generation article 9 is put in theoverheated state, the flavor and taste of aerosols generated by theaerosol generation article 9 may be impaired.

The control unit 8 may be configured to control the power that issupplied from the power source 4 to the load 3 by the feedback control,after supplying the necessary amount of power to the load 3. In thisway, the feedback control is executed after the necessary amount ofpower is supplied to the load 3, so that it is possible to improvecontrol accuracy after the necessary amount of power is supplied to theload 3 by the feedback control of which control stability is excellent,thereby stabilizing the aerosol generation.

The feed-forward control that is executed by the control unit 8 isdivided into a first sub-phase and a second sub-phase, and values ofvariables that are used in the feed-forward control in the firstsub-phase and the second sub-phase may be set different. In this case,the different values of variables may include different controlvariables, different constants and different threshold values. In thisway, the feed-forward control is divided into the first sub-phase andthe second sub-phase and the different values of variables are used, sothat it is possible to improve the control accuracy, as compared to acase where one control phase is used. In the meantime, functions oralgorithms that are used in the feed-forward control in the firstsub-phase and the second sub-phase may be set different. The firstsub-phase and the second sub-phase will be described in detail laterwith reference to FIGS. 4 to 8 .

It is assumed that the first sub-phase is executed earlier than thesecond sub-phase, for example.

The power (W) or the amount of power (W·h) that is supplied to the load3 in the first sub-phase may be set greater than the power (W) or theamount of power (W·h) that is supplied to the load 3 in the secondsub-phase. Thereby, since a rate of temperature increase of the load 3is gentle or the increase in temperature of the load 3 stops in thesecond sub-phase, it is possible to stabilize the temperature of theload 3 after the feed-forward control is over.

A time period of the first sub-phase may be set longer than a timeperiod of the second sub-phase. In this way, the time of the firstsub-phase in which the state (temperature) of the load 3 is dominantlychanged is set longer than the second sub-phase, so that it is possibleto resultantly shorten a total time period of the feed-forward control.In other words, the aerosol generation device 1 can more rapidlygenerate aerosols having desired flavor and taste from the aerosolgeneration article 9.

The control unit 8 may be configured to execute the feed-forward controlso that the load 3 is in the use state at the end of the secondsub-phase. Thereby, it is possible to stably make the temperature of theload 3 reach a temperature, which is necessary in the use state, byusing the feed-forward control until the second sub-phase is over. Also,since an amount of power that is discharged by the power source 4 isreduced, as compared to a case where the load 3 is in the use statebefore the second sub-phase is over, it is possible to suppressdeterioration in the power source 4, in addition to improving specificpower consumption of the power source 4.

The control unit 8 may be configured to execute the feed-forward controlso as to supply the power or the amount of power that is necessary so asto put the load 3 in the use state in which aerosols can be generatedand to keep the use state of the load 3, in the second sub-phase. Inthis way, the power or the amount of power that is necessary so as tokeep the use state in the second sub-phase is supplied to the load 3, sothat it is possible to avoid the supply of extremely low power orextremely small amount of power in the second sub-phase. Therefore, itis possible to suppress situations where the load 3 is not in the usestate, the aerosol generation device 1 cannot generate aerosols havingdesired flavor and taste from the aerosol generation article 9 in theuse phase, and the specific power consumption of the power source 4 arelowered.

The control unit 8 may be configured to execute the feed-forward controlso that be load 3 is in the use state, before the first sub-phase ischanged to the second sub-phase. Thereby, it is possible to put the load3 in the use state at the early stage at the time of the first sub-phaseand to keep the use state by adjusting the temperature of the load 3 inthe second sub-phase, which increase the control stability.

The control unit 8 may be configured to execute the feed-forward controlso as to supply the power or the amount of power, which is necessary soas to keep the use state, to the load 3 that is in the use state, in thesecond sub-phase. Thereby, it is possible to suppress a situation wherethe extremely low power or extremely small amount of power is suppliedin the second sub-phase and the load 3 is not thus put in the use state.As a result, it is possible to stabilize the load 3 in the use state.Also, it is possible to suppress variation in the temperature of theload 3 at the end of the second sub-phase.

The second sub-phase may be set shorter than the first sub-phase andequal to or longer than a unit time of control that is implemented (canbe implemented) by the control unit 8, for example. Thereby, the secondsub-phase is executed for an appropriate time period, so that it ispossible to stabilize the temperature of the load 3.

The control unit 8 may be configured to change the values of variablesthat are used in the feed-forward control, based on an initial statethat is a state during or before the execution of the feed-forwardcontrol of the load 3. In this case, the initial state includes aninitial temperature and the like, for example. The change of the valuesof variables includes change of a control variable, change of aconstant, and change of a threshold value. In this way, the values ofvariables that are used in the feedback control are changed based on theinitial state, so that it is possible to suppress the variation in thetemperature of the load 3 during execution and/or at the end of theteed-forward control, which may be caused due to external factors suchas a product error, an initial condition, an atmospheric temperature andthe like.

The control unit 8 may be configured to change the values of variablesso as to supply the power or the amount of power, which is necessary forthe load 3 in the initial state to shift to the use state, to the load3. Thereby, it is possible to suppress the variation in the temperatureof the load 3 in the use state at the end of the feedback control, whichmay be caused due to external factors such as a product error, aninitial condition, an atmospheric temperature and the like.

The control unit 8 may be configured to acquire a value relating to aremaining amount of the power source 4, and to change the values ofvariables that are used in the feed-forward control, based on the valuerelating to the remaining amount during or before the execution of thefeed-forward control. Thereby, it is possible to suppress the variationin the temperature of the load 3, which may be caused due to adifference in the remaining amount of the power source 4.

The control unit 8 may be configured to increase at least one of a dutyratio, a voltage, and an on-time of the power that is supplied from thepower source 4 to the load 3 as the value relating to the remainingamount is smaller. For example, in a case where a DC/DC converter isused, a pulse wave may not be applied to the load 3 due to a smoothingaction of a smoothing capacitor provided on an output-side of the DC/DCconverter. Therefore, the control unit 8 may control a time (on-time)during which the power is supplied to the load 3, based on the valuerelating to the remaining amount. Thereby, it is possible to suppressthe variation in the temperature of the load 3, which is caused due to adifference in the remaining amount of the power source 4.

The control unit 8 may be configured to change the values of variablesso that a first amount of power, which is supplied from the power source4 to the load 3 based on a value relating to a first remaining amountacquired from the power source 4, is substantially the same as a secondamount of power, which is supplied from the power source 4 to the load 3based on a value relating to a second remaining amount acquired from thepower source 4 and different from the value relating to the firstremaining amount. Thereby, for example, the PWM control can be executedso that the constant power is supplied to the load 3, irrespective ofthe remaining amount of the power source 4. As a result, it is possibleto suppress the variation in the temperature of the load 3, which iscaused due to a difference in the remaining amount of the power source4.

The control unit 8 may be configured to acquire a value relating to aremaining amount of the power source 4, and to change the values ofvariables that are used in the feed-forward control, based on a state ofthe load 3 during or before the execution of the feed-forward controland the value relating to the remaining amount. Thereby, it is possibleto suppress the variation in the temperature of the load 3 during theexecution and/or at the end of the feed-forward control, which may becaused due to external factors such as a product error, an initialcondition, an atmospheric temperature and the like, in addition to adifference in remaining amount of the power source 4.

The control unit 8 may be configured to decrease at least one of a dutyratio, a voltage, and an on-time of the power that is supplied from thepower source 4 to the load 3 as the load 3 is closer to the use state inwhich the load can generate aerosols, and to decrease at least one of aduty ratio, a voltage, and an on-time of the power as the value relatingto the remaining amount is larger, based on the state of the load 3. Inthis case, for example, at least one of a duty ratio, a voltage, and anon-time of the power obtained from the state of the load 3 such as aninitial temperature can be corrected with the remaining amount of thepower source 4, so that it is possible to suppress the variation in thetemperature of the load 3 during the execution and/or at the end of thefeed-forward control, which may be caused the remaining amount of thepower source 4, in addition to the external factors such as a producterror, an initial condition, an atmospheric temperature and the like.

The control unit 8 may be configured to change the duty ratio, thevoltage and the on-time so that a first amount of power, which issupplied from the power source 4 to the load 3 based on a value relatingto a first remaining amount acquired from the power source 4, issubstantially the same as a second amount of power, which is suppliedfrom the power source 4 to the load 3 based on a value relating to asecond remaining amount acquired from the power source 4 and differentfrom the value relating to the first remaining amount. In this case, thefirst amount of power and the second amount of power may be setdifferent depending on the state of the load 3. Thereby, for example,the PWM control can be executed so that the same power in terms of thefirst remaining amount and the second remaining amount is supplied tothe load 3. As a result, it is possible to suppress the variation in thetemperature of the load 3 during execution and/or at the end of thefeed-forward control, which may be caused due to the remaining amount ofthe power source 4, in addition to the external factors such as aproduct error, an initial condition, an atmospheric temperature and thelike.

The control unit 8 may be configured to change the values of variablesthat are used in the feed-forward control, based on a resistance valueof the load 3 or a deterioration state in the load 3 during or beforethe execution of the feed-forward control. In this case, the controlunit 8 may be configured to obtain the deterioration state, based on thenumber of uses or a cumulative value of use times of the load 3, forexample. Thereby, even when the load 3 is deteriorated and thus theelectric resistance value at room temperatures and the like changes asthe number of uses of the aerosol generation device 1 increases, thetemperature of the load 3 can be stabilized. Also, even when the load 3having a positive temperature coefficient characteristic (PTCcharacteristic) is used and the load 3 is deteriorated and thecharacteristic thereof changes, the temperature of the load 3 can bestabilized.

The diverse controls by the control unit 8 may also be implemented asthe control unit 8 executes a program.

Regarding the first embodiment, specific control examples are furtherdescribed in following embodiments 1A to 1E.

Example 1A

FIG. 4 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 1A.

The preparation unit 10 of the control unit 8 acquires the timer value tthat is output by the timer 5 and obtains a duty command valuecorresponding to the timer value t, in the preparation phase. Thecontrol unit 8 switches a switch 25 provided in a circuit forelectrically connecting the load 3 and the power source 4, as shown inFIG. 9 , according to the obtained duty command value, therebycontrolling the power that is supplied to the load 3, based on the dutycommand value.

In Example 1A, a heating state for the load 3 is switched based on theduty command value, more specifically, the duty ratio indicated by theduty command value. However, when controlling a DC/DC converter providedin the circuit for electrically connecting the load 3 and the powersource 4, instead of the switch 25, the heating state for the load 3 maybe switched based on the current that is supplied to the load 3, thevoltage that is applied to the load 3 or command values thereof, forexample, and a value for instructing the heating state for the load 3may be changed as appropriate.

The preparation phase further includes the first sub-phase and thesecond sub-phase. The first sub-phase and the second sub-phase may alsobe distinguished by the duty command value, more specifically, the dutyratio indicated by the duty command value. Also, the first sub-phase andthe second sub-phase may be distinguished by the current that issupplied to the load 3, the voltage that is applied to the load 3 orcommand values thereof.

A time period Δt₁ of the first sub-phase is a time period from start ofthe supply of power to the load 3 in the non-operation state to time t₁.

A time period Δt₂ of the second sub-phase is a time period from time t₁to end time t₂ of the preparation phase.

The time period Δt₁ of the first sub-phase is longer than the timeperiod Δt₂ of the second sub-phase.

A duty ratio D₁ in the first sub-phase is greater than a duty ratio D₂in the second sub-phase. In Example 1A, the power that is supplied fromthe power source 4 to the load 3 is set greater as the duty ratioincreases. Therefore, the power that is supplied from the power source 4to the load 3 in the first sub-phase is greater than the power that issupplied from the power source 4 to the load 3 in the second sub-phase.

In the first sub-phase, the control unit 8 controls the power that issupplied to the load 3, based on the duty command value indicative of alarge duty ratio, until the temperature of the load 3 (aerosolgeneration article 9) reaches an aerosol generation temperature.Thereby, it is possible to generate aerosols from the aerosol generationarticle 9 at the early stage from start of the supply of power (powerfeeding) from the power source 4 to the load 3.

In the second sub-phase, the control unit 8 controls the power that issupplied to the load 3, based on a duty command value indicative of theduty ratio smaller than the duty ratio of the first sub-phase, so as tosuppress variation in the temperature of the load 3 until the loadshifts to the use phase, and to keep the temperature of the load 3(aerosol generation article 9) to the aerosol generation temperature orhigher. Even when a temperature at the end of the first sub-phaseslightly varies, the control unit 8 suppresses and absorbs the variationby the control in the second sub-phase. Thereby, the flavor and taste ofaerosols that are generated from the aerosol generation article 9 in theuse phase become stable.

In this way, in the preparation phase, the high power is supplied to theload 3 to quickly increase the temperature of the load 3 by the firstsub-phase and the low power for heat retention is supplied to the load 3by the second sub-phase, so that it is possible to stabilize the amountof aerosol generation and the flavor and taste thereof in the use phaseafter the preparation phase.

FIG. 5 is a flowchart depicting an example of processing in thepreparation phase by the control unit 8 in accordance with Example 1A.

In step S501, the preparation unit 10 determines whether there is arequest for aerosol generation. When it is determined that there is norequest for aerosol generation (“No” in step S501), the preparation unit10 repeats step S501. As a first example, the preparation unit 10 maydetermine in step S501 whether there is a request for aerosolgeneration, based on whether an input for starting heating of the load 3is made from a user. More specifically, when an input for startingheating of the load 3 is made from a user, the preparation unit 10 maydetermine that there is a request for aerosol generation. On the otherhand, when an input for starting heating of the load 3 is not made froma user, the preparation unit 10 may determine that there is no requestfor aerosol generation. As a second example, the aerosol generationdevice 1 has a sensor for detecting user's inhalation, which is notshown in FIG. 1 , and may use user's inhalation detected by the sensor,as an input for starting heating of the load 3. As a third example, theaerosol generation device 1 has at least one of a button, a switch, atouch panel and a user interface, which are not shown in FIG. 1 , andmay use an operation thereon, as an input for starting heating of theload 3.

When it is determined that there is a request for aerosol generation,the preparation unit 10 activates the timer 5, in step S502.

In step S503, an input of the timer value t from the timer 5 to thepreparation unit 10 starts.

In step S504, the preparation unit 10 switches the switch 25 provided inthe circuit for electrically connecting the load 3 and the power source4, which is shown in FIG. 9 , based on the duty command value indicativeof the duty ratio D₁ in the first sub-phase, thereby controlling thepower that is supplied to the load 3.

In step S505, the preparation unit 10 determines whether the timer valuet is the end time t₁ or longer of the first sub-phase. When it isdetermined that the timer value t is not the end time t₁ or longer ofthe first sub-phase (a determination result in step S505 is “No”), thepreparation unit 10 repeats step S505.

When it is determined that the timer value t is the end time t₁ orlonger of the first sub-phase (a determination result in step S505 is“Yes”), the preparation unit 10 controls the power that is supplied tothe load 3, based on the duty command value indicative of the duty ratioD₂ in the second sub-phase, in step S506.

In step S507, the preparation unit 10 determines whether the timer valuet is the end time t₂ or longer of the second sub-phase. When it isdetermined that the timer value t is not the end time t₂ or longer ofthe second sub-phase (a determination result in step S507 is “No”), thepreparation unit 10 repeats step S507. When it is determined that thetimer value t is the end time t₂ or longer of the second sub-phase (adetermination result in step S507 is “Yes”), the preparation unit 10ends the preparation phase and shifts to the use phase.

In Example 1A as described above, the control unit 8 controls theheating of the load 3 by using the feed-forward control in thepreparation phase. Therefore, after there is a request for aerosolgeneration and the supply of power from the power source 4 to the load 3starts, it is possible to increase the rate of temperature increase ofthe load 3.

In Example 1A, in the preparation phase, the feed-forward controlincreases the temperature of the load 3 to a temperature at whichaerosols can be inhaled. Therefore, it is possible to shorten a timeafter the aerosol generation is requested until the user can inhaleaerosols.

In Example 1A, since the power that is supplied to the load 3 in thefirst sub-phase of the preparation phase is once increased and then thepower that is supplied to the load 3 in the second sub-phase of thepreparation phase is lowered, it is possible to suppress the load 3 frombeing overheated.

The control unit 8 controls the heating of the load 3 by using thefeed-forward control in the preparation phase, so that it is possible toincrease the rate of temperature increase of the load 3 after there is arequest for aerosol generation and the supply of power from the powersource 4 to the load 3 starts, it is possible to shorten a time afterthe aerosol generation is requested until the user can inhale aerosolsand it is possible to suppress the load 3 from being overheated. Herein,the reasons are described in detail. For example, if the control unit 8controls the heating of the load 3 by using the feedback control in thepreparation phase, a control amount affects a decision of the operatingamount, so that the rate of temperature increase of the load 3 is likelyto be slow. Also, due to the similar reason, the time after the aerosolgeneration is requested until the user can inhale aerosols is likely tolengthen. In particular, in an aspect where the load 3 is heated to thetemperature at which aerosols can be generated from a relatively earlystage of the preparation phase, when a gain is small, the rate oftemperature increase of the load 3 is slow, and when the gain is large,the temperature of the load 3 is difficult to converge to thetemperature at which aerosols can be generated, so that the load 3 islikely to be overheated. Also, in an aspect where the target temperatureof the load 3 is gradually increased over time, stagnation intemperature increase may occur when the measured temperature value ofthe load 3 reverses the target temperature. However, when the controlunit 8 controls the heating of the load 3 by using the teed-forwardcontrol in the preparation phase, the concerns do not occur. Therefore,it is possible to increase the rate of temperature increase of the load3 after there is a request for aerosol generation and the supply ofpower from the power source 4 to the load 3 starts. Also, it is possibleto shorten a time after the aerosol generation is requested until theuser can inhale aerosols. In addition to this, it is possible tosuppress the load 3 from being overheated, and to shorten a time untilthe load 3 is in the use state. Therefore, it can be said that thefeed-forward control is more preferable than the feedback control, asthe control that is used for the heating of the load 3 in thepreparation phase.

Example 1B

In Example 1B, control of changing the power that is supplied to theload 3 in the first sub-phase on the basis of the measured temperaturevalue indicative of the temperature of the load 3 is described.

FIG. 6 is a graph depicting an example of a state in which a temperatureof the load is uneven between the preparation phase and the use phase.FIG. 6 is a graph depicting an example of a relation between the timervalue t and the temperature of the load 3 and a relation between thetimer value t and the power that is supplied from the power source 4 tothe load 3. The horizontal axis indicates the timer value t. Thevertical axis indicates the temperature of the load 3 or the duty ratioof the power that is supplied to the load 3.

Even though the preparation phase is over, the temperature of the load 3may rapidly vary from the preparation phase end temperature when theload shifts from the preparation phase to the use phase or immediatelyafter the shift to the use phase.

When the preparation phase end temperature is not stable at or near theaerosol generation temperature, the temperature of the load 3 shows thesharp variation, so that the temperature of the load 3 may not reach theaerosol generation temperature at least at the early stage of the usephase.

As factors that cause the temperature of the load 3 to vary when thepreparation phase is over, three following factors may be assumed, forexample.

A first factor is a shift in the initial state of the load 3, forexample, a shift in the temperature of the load 3 at the time when thetemperature increase of the load 3 starts.

A second factor is a shift in the output voltage of the power source 4,which can be caused due to reduction in the remaining amount ordeterioration of the power source 4.

A third factor is a product error of the aerosol generation article 9 orthe aerosol generation device 1.

The first and second factors can be at least relaxed by performingfollowing control the first sub-phase.

The third factor can be at least relaxed by heat-retention control inthe second sub-phase.

FIG. 7 is a graph depicting an example of control on the duty ratio D₁in the first sub-phase. FIG. 7 depicts a relation between the timervalue t and the temperature of the load 3, and a relation between thetimer value t and the duty ratio. The horizontal axis indicates thetinier value t. The vertical axis indicates the temperature of the load3 or the duty ratio of the power that is supplied to the load 3.

If the duty ratio D₁ in the first sub-phase is set constant and the dutyratio D₂ in the second sub-phase is set constant, when the temperatureof the load 3 is low or high at the start of the first sub-phase, thetemperature of the load 3 is also low or high at the end of the secondsub-phase and the temperature of the load 3 varies at the end of thepreparation phase.

In contrast, the control unit 8 in accordance with Example 1B changesthe duty ratio D₁ in the first sub-phase, based on the measuredtemperature value at the start of the first sub-phase, therebysuppressing the variation in the temperature of the load 3 at the end ofthe preparation phase, based on the shift in the temperature of the load3 at the start of the first sub-phase.

More specifically, when the measured temperature value at the start ofthe first sub-phase is small, the control unit 8 increases the dutyratio D₁ in the first sub-phase. In contrast, when the measuredtemperature value at the start of the first sub-phase is large, thecontrol unit 8 decreases the duty ratio D₁ in the first sub-phase.

FIG. 8 is a flowchart depicting an example of processing in thepreparation phase by the control unit 8 in accordance with Example 1B.

The processing from step S801 to step S803 is the same as the processingfrom step S501 to step S503 in FIG. 5 .

In step S804, a measured temperature value T_(start) at the start of thefirst sub-phase is input, as the initial state, from the temperaturemeasurement unit 6 to the preparation unit 10.

In step S805, the preparation unit 10 obtains the duty ratio D₁(T_(start)) in the first sub-phase, based on the measured temperaturevalue T_(start), and switches the switch 25 provided in the circuit forelectrically connecting the load 3 and the power source 4, as shown inFIG. 9 , based on the duty command value indicative of the duty ratio D₁(T_(start)) in the first sub-phase, thereby controlling the power thatis supplied to the load 3.

The processing from step S806 to step S808 is the same as the processingfrom step S505 to step S507 in FIG. 5 .

In Example 1B as described above, it is possible to suppress thevariation in temperature of the load 3 at the end of the preparationphase, based on the shift in temperature of the load 3 at the start ofthe first sub-phase, so that it is possible to stabilize the amount ofaerosol generation and the favor and taste thereof in the use phaseafter the preparation phase.

In Example 1B, the control unit 8 changes the duty command value in thefirst sub-phase, based on the measured temperature value T_(start) atthe start of the first sub-phase. However, the control unit 8 may changethe duty command value in the second sub-phase based on the measuredtemperature value T_(start), or may change both the duty command valuein the first sub-phase and the duty command value in the secondsub-phase, based on the measured temperature value T_(start).

Example 1C

In Example 1C, control of changing the power in the first sub-phasebased on the SOC of the power source 4 as an example of the valuerelating to the remaining amount of the power source 4 or PWM control ofmaking the voltage applied to the load 3 constant even when the SOC ofthe power source 4 changes is described.

FIG. 9 depicts an example of a relation between current that flows fromthe power source 4 to the load 3 and a voltage that is applied to theload 3 by the power source 4. An ammeter 23 outputs current A that flowsfrom the power source 4 to the load 3, and a voltmeter 24 outputs avoltage V that is applied from the power source 4 to the load 3. Also,the control unit 8 (not shown in FIG. 9 ) acquires a value output fromthe ammeter 23 and a value output from the voltmeter 24. In themeantime, as the ammeter 23 and the voltmeter 24, an ammeter and avoltmeter each having a shunt resistor having a known resistance valueembedded therein may be used or a Hall element may be used. In themeantime, it is advantageous to use those in which a shunt resistor isembedded, from a standpoint of a weight or volume, and to use the Hallelement, from a standpoint of measurement accuracy or less affecting ameasurement target. Also, the ammeter 23 or the voltmeter 24 may outputa measured value as a digital value or an analog value. When the ammeter23 or the voltmeter 24 outputs an analog value, the control unit 8 mayconvert the analog value into a digital value by an A/D converter.

Also, the power source 4 and the load 3 are electrically connected bythe circuit, so that when the control unit 8 opens/closes (switches) theswitch 25 provided in the circuit, the supply of power from the powersource 4 to the load 3 is controlled. As an example, the switch 25 mayconsist of at least one of a switch, a contactor and a transistor. Inthe meantime, the circuit may also have a DC/DC converter, instead ofthe switch 25 or in addition to the switch 25. In this case, the controlunit 8 controls the DC/DC converter, thereby controlling the supply ofpower from the power source 4 to the load 3.

In FIG. 9 , the voltmeter 24 is provided closer to the load 3 than theswitch 25. However, in order to use the SOC-OCV method so as to acquirethe SOC of the power source 4, other voltmeter may be provided closer tothe power source 4 than the switch 25. The other voltmeter enables anoutput of an open end voltage (OCV) of the power source 4.

FIG. 10 is a graph depicting an example of a relation between an outputvoltage and an output current corresponding to the remaining amount ofthe power source 4 in the first sub-phase of the preparation phase. InFIG. 10 , the horizontal axis indicates the tinier value t, and itshould be noted that the second sub-phase after time t₁ is omitted. Thevertical axis indicates the voltage or current that is output from thepower source 4. Also, in FIG. 10 , the broken line indicates the voltageand current when the remaining amount of the power source 4 is 100%. Thesolid line indicates the voltage and current when the discharge-endvoltage or a voltage close to the discharge-end voltage is outputbecause the remaining amount of the power source 4 is at or near 0%. InFIG. 10 , V_(full-charged) and Wan indicate the full-charged voltage andthe discharge-end voltage of the power source 4, respectively.

In FIG. 10 , it is assumed that the duty ratio D₁ in the first sub-phaseis 100%.

For simplification, when it is assumed that the electric resistance ofthe circuit for electrically connecting the load 3 and the power source4 is negligibly small and the circuit is not a target that the powersource 4 supplies power at the same time with the load 3, the outputcurrent corresponding to the remaining amount of the power source 4 isobtained by dividing the output voltage of the power source 4 by aresistance value R of the load 3.

The current I_(full-charged) that is output when the output voltage ofthe power source 4 is the full-charged voltage is obtained by thefull-charged voltage/the resistance of the load 3 (V_(full-charged)/R),when the simplified model as described above is used.

The current I_(E.O.D) that is output when the Output voltage of thepower source 4 is the discharge-end voltage is obtained by thedischarge-end voltage/the resistance of the load 3 (V_(E.O.D)/R), whenthe simplified model as described above is used.

In the first sub-phase of the preparation phase, the currentV_(full-charged)/R that is output when the output voltage of the powersource 4 is the full-charged voltage V_(full-charged) is greater thanthe current V_(E.O.D)/R that is output when the output voltage of thepower source 4 is the discharge-end voltage V_(E.O.D).

FIG. 11 is a graph depicting an example of comparison between a changein temperature of the load 3 in the preparation phase when a voltage ofthe power source 4 is the full-charged voltage at the start of the firstsub-phase and a change in temperature of the load 4 in the preparationphase when a voltage of the power source 4 is near the discharge-endvoltage at the start of the first sub-phase, in a case where the dutyratio is constant. In FIG. 11 , the horizontal axis indicates the timervalue t. The vertical axis indicates the temperature or the duty ratioof the power that is supplied to the load 3. As described above, thecurrent that is supplied from the power source 4 to the load 3 and thevoltage that is applied when the power source 4 is near thedischarge-end voltage are smaller, as compared to a case where the powersource 4 is at the full-charged voltage. Therefore, the change intemperature of the load 3 in the preparation phase when the power source4 is at the full-charged voltage is larger than the change intemperature of the load 3 in the preparation phase when the power source4 is near the discharge-end voltage.

In the meantime, when the power source 4 is at the full-charged voltage,the power that is supplied from the power source 4 to the load 3 in thefirst sub-phase is expressed by a following equation.W=(V _(full-charged) ·D)² /R

On the other hand, when the power source 4 is near the discharge-endvoltage, the power that is supplied from the power source 4 to the load3 in the first sub-phase is expressed by a following equation.W=(V_(E.O.D) ·D)² /R

In both the equations, D indicates the duty ratio of the power that issupplied to the load 3.

A difference between both the equations is obtained. A differencebetween the power that is supplied from the power source 4 to the load 3in the first sub-phase when the power source 4 is at the full-chargedvoltage and the power that is supplied from the power source 4 to theload 3 in the first sub-phase when the power source 4 is near thedischarge-end voltage is expressed by a following equation.ΔW={(V _(full-charged) ·D)²−(V _(E.O.D) ·D)² }/R

For example, when the full-charged voltage V_(full-charged) is 4.2V, thedischarge-end voltage V_(E.O.D) is 3.2V, the electric resistance value Rof the load 3 is 1.0Ω and the duty ratio D is 100%, the power differenceΔW is 7.4 W.

For this reason, even when diverse conditions such as a condition (forexample, a contact area and the like) relating to heat transfer betweenthe load 3 and the aerosol generation article 9, an initial temperatureof the load 3, a heat capacity of the aerosol generation article 9 andthe like are the same, the temperature of the load 3 at the end of thepreparation phase changes according to the remaining amount of the powersource 4.

Therefore, in Example 1C, the control unit 8 changes the power in thefirst sub-phase, i.e., the duty ratio, based on the output voltage ofthe power source 4, thereby suppressing the variation in temperature ofthe load 3 at the end of the preparation phase.

Also, in Example 1C, the control unit 8 may execute the PWM control ofmaking the voltage to be applied to the load 3 constant so as to excludethe influence of the output voltage of the power source 4. In the PWMcontrol, a pulsed voltage waveform is changed so that an area of aneffective voltage waveform is the same. Herein, the effective voltagecan be obtained from “applied voltage×duty ratio”. In another example,the effective voltage may be obtained from a root mean square (RMS).

FIG. 12 is a graph exemplifying a relation between the output voltageand the output current of the power source 4 when the PWM control isperformed according to the remaining amount of the power source 4. InFIG. 12 , the horizontal axis indicates the timer value t, and it shouldbe noted that the second sub-phase after time t₁ is omitted. Thevertical axis indicates the voltage or current that is output from thepower source 4.

In the preparation phase, the control unit 8 performs control so that anarea of a pulsed voltage waveform corresponding to the full-chargedvoltage V_(full-charged) is the same as an area of a voltage waveformcorresponding to the discharge-end voltage V_(E.O.D).

The equation (1) indicates a relation among the duty ratioD_(full-charged) corresponding to the full-charged voltageV_(full-charged), the full-charged voltage V_(full-charged), thedischarge-end voltage V_(E.O.D), and the duty ratio D_(E.O.D)corresponding to the discharge-end voltage V_(E.O.D).

$\left\lbrack {{equation}1} \right\rbrack\begin{matrix}{D_{{full}\_{charged}} = {\frac{V_{E.O.D} \cdot D_{E.O.D}}{V_{{full}\_{charged}}} = {\frac{3.2 \times 100\%}{4.2} \cong 0.76}}} & (1)\end{matrix}$

In the equation (1), when the duty ratio D_(E.O.D) all corresponding tothe discharge-end voltage V_(E.O.D) is set to 100%, the duty ratioD_(full-charged) corresponding to the full-charged voltageV_(full-charged) is 76%.

In this way, the control unit 8 can suppress the variation intemperature of the load 3 at the end of the preparation phase bycontrolling the duty ratio based on the output voltage of the powersource 4 in the first sub-phase included in the preparation phase.

FIG. 13 is a flowchart depicting an example of processing in thepreparation phase by the control unit 8 in accordance with Example 1C.

The processing from step S1301 to step S1303 is the same as theprocessing from step S501 to step S503 in FIG. 5 .

In step S1304, the power source measurement unit 7 measures the outputvoltage (battery voltage) V_(Batt) of the power source 4.

In step S1305, the preparation unit 10 obtains the duty ratioD₁=(V_(E.O.D)·D_(E.O.D))/V_(Batt).

In step S1306, the preparation unit 10 switches the switch 25 providedin the circuit for electrically connecting the load 3 and the powersource 4, as shown in FIG. 9 , based on the duty command valueindicative of the duty ratio D₁, thereby controlling the power that issupplied to the load 3.

The processing from step S1307 to step S1309 is the same as theprocessing from step S505 to step S507 in FIG. 5 .

In Example 1C as described above, the duty ratio D₁ in the firstsub-phase included in the preparation phase is changed according to theoutput voltage of the power source 4 that is an example of the valuerelating to the remaining amount of the power source 4, so that thevariation in temperature of the load at the end of the preparation phasecan be suppressed. Therefore, it is possible to stabilize the amount ofaerosol generation and the flavor and taste in the use phase after thepreparation phase.

In Example 1C, the aspect where the output voltage of the power source 4is used as an example of the value relating to the remaining amount ofthe power source 4 has been described. Instead, the duty ratio D₁ in thefirst sub-phase included in the preparation phase may be changedaccording to the SOC of the power source 4, as another example of thevalue relating to the remaining amount of the power source 4.

In the case where the SOC is used as the value relating to the remainingamount of the power source 4, the SOC is defined as 100% when thevoltage of the power source 4 is the full-charged voltage, as wellknown. On the other hand, the SOC is defined as 0% when the voltage ofthe power source 4 is the discharge-end voltage. Also, the SOC changescontinuously from 100% to 0% according to the remaining amount of thepower source 4. When a lithium-ion secondary battery is used as thepower source 4, the full-charged voltage and the discharge-end voltageare 4.2V and 3.2V, respectively, for example. However, the full-chargedvoltage and the discharge-end voltage of the power source 4 are notlimited thereto. As described above, the control unit 8 may obtain theSOC of the power source 4 by the SOC-OCV method, the current integrationmethod (Coulomb counting method) or the like.

Example 1D

In order to control the temperature of the load 3 at the end of thepreparation phase with higher accuracy, the control is preferablyperformed based on a plurality of initial conditions, for example, bothvalues relating to the temperature of the load 3 and the remainingamount of the power source 4.

In Example 1D, the feed-forward control of obtaining the duty ratioD_(E.O.D) (T_(HTR)) corresponding to the discharge-end voltageV_(E.O.D), based on the measured temperature value T_(HTR), obtainingthe duty ratio D₁ in the first sub-phase, based on the discharge-endvoltage V_(E.O.D), the duty ratio D_(E.O.D) (T_(HTR)), and the batteryvoltage V_(Batt), and switching the switch 25 provided in the circuitfor electrically connecting the load 3 and the power source 4 as shownin FIG. 9 by using the duty ratio D₁ is performed.

FIG. 14 is a graph depicting an example of control that is executed bythe control unit 8 in accordance with Example 1D. In FIG. 14 , thehorizontal axis indicates the timer value t. The vertical axis indicatesthe temperature or the duty ratio of the power that is supplied to theload 3.

The left graph of FIG. 14 pictorially depicts a relation between theduty ratio and the change in temperature of the load 3. In the leftgraph of FIG. 14 , only the duty ratio D₁ in the first sub-phase of theduty ratio D₁ in the first sub-phase and the duty ratio D₂ in the secondsub-phase is changed. When the duty ratio D₁ is set to the large dutyratio shown with the thick solid line, the temperature of the load 3changes as shown with the solid line in the left upper graph of FIG. 14, for example. On the other hand. When the duty ratio D₁ is set to thesmall duty ratio shown with the thin solid line, the temperature of theload 3 changes as shown with the dotted line in the left upper graph ofFIG. 14 , for example. As shown in the left graph of FIG. 14 , thetemperature of the load 3 changes according to the level (height) of theduty ratio D₁ in the first sub-phase, i.e., the temperature of the load3 is different at each timer value t.

That is, even though the initial conditions such as values relating tothe temperature of the load 3 and the remaining amount of the powersource 4 are different, when the duty ratio D₁ in the first sub-phase isadjusted, the temperature of the load 3 at the end of the preparationphase can be controlled further highly.

Therefore, the control unit 8 in accordance with Example 1D performscontrol so that the higher the temperature of the load 3 (initialtemperature) at the start of the first sub-phase is, the smaller theduty ratio D₁ in the first sub-phase is, and the lower the temperatureof the load 3 at the start of the first sub-phase is, the larger theduty ratio D₁ in the first sub-phase is, as shown in the right graph ofFIG. 14 .

In the meantime, the control unit 8 in accordance with Example 1D maychange the duty ratio D₁, based on the value (for example, the outputvoltage of the power source 4) relating to the remaining amount of thepower source 4, in addition to the temperature of the load 3 at thestart of the first sub-phase. In this way, as shown in the right graphof FIG. 14 , even though the initial conditions such as values relatingto the temperature of the load 3 and the remaining amount of the powersource 4 are different, it is possible to control further highly thetemperature of the load 3 at the end of the preparation phase and toapproach the same to a specific value.

FIG. 15 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 1D.

In Example 1D, the control unit 8 includes an initial setting unit 16,and a preparation unit 10.

The initial setting unit 16 has a relation between the temperature ofthe load 3 and the duty ratio D_(E.O.D) corresponding to thedischarge-end voltage V_(E.O.D).

The initial setting unit 16 receives the measured temperature valueT_(HTR) at the start of the first sub-phase from the temperaturemeasurement unit 6, and obtains a duty ratio D_(E.O.D) (T_(HTR))corresponding to the discharge-end voltage V_(E.O.D), based on therelation between the temperature and the duty ratio and the measuredtemperature value T_(HTR).

Also, the initial setting unit 16 inputs the voltage V_(Batt) from thepower source measurement unit 7, obtains the duty ratioD₁=V_(E.O.D)·D_(E.O.D) (T_(HTR))/V_(Batt), and outputs the duty commandvalue indicative of the duty ratio D₁ to the preparation unit 10.

When the timer value t is input from the timer 5 to the preparation unit10, the preparation unit 10 determines whether the timer value t is inthe first sub-phase or the second sub-phase, controls the power that issupplied to the load 3, based on the duty command value indicative ofthe duty ratio D₁ in the first sub-phase, and controls the power that issupplied to the load 3, based on the duty command value indicative ofthe duty ratio D₂ in the second sub-phase.

FIG. 16 is a flowchart depicting an example of processing in thepreparation phase by the control unit 8 in accordance with Example 1D.

The processing from step S1601 to step S1603 is the same as theprocessing from step S501 to step S503 in FIG. 5 .

In step S1604, the measured temperature value T_(start) at the start ofthe first sub-phase is input from the temperature measurement unit 6 tothe initial setting unit 16.

In step S1605, the output voltage V_(Batt) of the power source 4 isinput from the power source measurement unit 7 to the initial settingunit 16.

In step S1606, the initial setting unit 16 obtains the duty ratioD_(E.O.D) (T_(start)) corresponding to the discharge-end voltageV_(E.O.D), based on the relation between the temperature and the dutyratio and the measured temperature value T_(start) input in step S1604,and obtains the duty ratio D₁=_(E.O.D)·D_(E.O.D) (T_(start))/V_(Batt),based on the voltage V_(Batt) and the duty ratio D_(E.O.D) (I_(start)).

In step S1607, the preparation unit 10 switches the switch 25 providedin the circuit for electrically connecting the load 3 and the powersource 4 as shown in FIG. 9 , based on the duty ratio D₁, therebycontrolling the power that is supplied to the load 3.

The processing from step S1608 to step S1610 is the same as theprocessing from step S505 to step S507 in FIG. 5 .

As described above, the control unit 8 in accordance with Example 1Dchanges the duty ratio D₁ in the first sub-phase, based on the valuesrelating to the initial temperature of the load 3 and the remainingamount of the power source 4. More specifically, the initial settingunit 16 obtains the duty ratio D_(E.O.D) (T_(start)) corresponding tothe discharge-end voltage V_(E.O.D), based on the relation between thetemperature and the duty ratio and the measured temperature valueT_(start), and obtains the duty ratio D₁ corresponding to the firstsub-phase, based on the discharge-end voltage V_(E.O.D), the duty ratioD_(E.O.D) (T_(start)), and the voltage V_(Batt). Thereby, it is possibleto control further highly the temperature of the load 3 at the end ofthe preparation phase even by the feed-forward control in which acontrol amount of a control target is not used as a feedback componentfor determining the operating amount.

Example 1E

In Example 1E, it is described that the feed-forward control is changedbased on deterioration in the load 3 in the preparation phase.

When the total number of uses N_(sum) of the load 3 increases, animpair, an oxidation phenomenon and the like occur, so that the load 3is deteriorated. When the load 3 is deteriorated, the electricresistance value R_(HTR) of the load 3 tends to increase. That is, thereis a correlation between the total number of uses N_(sum) indicative ofa deterioration state in the load 3 and the electric resistance valueR_(HTR) of the load 3.

Therefore, in Example 1E, the power is supplied to the load 3 so thatthe temperature of the load 3 is stable even when the resistance valueR_(HTR) is increased due to the deterioration in the load 3. In thebelow, a method of supplying the power to the load 3 so that thetemperature of the load 3 is stable irrespective of the deteriorationstate in the load 3 is described in detail.

When the current that flows through the load 3 is denoted as I_(HTR),the voltage that is applied to the load 3 is denoted as V_(HTR), thepower that is supplied to the load 3 is denoted as P_(HTR), a resistanceof the load is denoted as R_(HTR), the output voltage of the powersource 4 is denoted as V, and the duty ratio of the power that issupplied to the load 3 is denoted as D, equations (2) and (3) areobtained, in the meantime, it should be noted that V_(HTR) is aneffective value of the voltage.

$\begin{matrix}\left\lbrack {{equation}2} \right\rbrack &  \\{I_{HTR} = \frac{V \cdot D}{R_{HTR}}} & (2)\end{matrix}$ $\begin{matrix}\left\lbrack {{equation}3} \right\rbrack &  \\{P_{HTR} = {{V_{HTR} \cdot I_{HTR}} = \frac{\left( {V \cdot D} \right)^{2}}{R_{HTR}}}} & (3)\end{matrix}$

Herein, the power is denoted as P_(HTR_new) when the load 3 is new (notdeteriorated), the resistance is denoted as R_(HTR_new) when the load 3is new, and the duty ratio is denoted as D_(new) when the load 3 is new.

Also, the power is denoted as P_(HTR_used) when the load 3 is old(deteriorated), the resistance is denoted as R_(HTR_used) when the load3 is old, and the duty ratio is denoted as D_(used) when the load 3 isold.

The power P_(HRT_new) when the load 3 is new is preferably the same asthe power P_(HTR_used) when the load 3 is old.

Therefore, a following equation (4) is obtained.

$\begin{matrix}{\left\lbrack {{equation}4} \right\rbrack} &  \\{P_{{HTR}\_{new}} = {\left. P_{{HTR}\_{used}}\rightarrow\frac{\left( {V \cdot D_{new}} \right)^{2}}{R_{{HTR}\_{new}}} \right. = {\left. \frac{\left( {V \cdot D_{used}} \right)^{2}}{R_{{HTR}\_{used}}}\rightarrow\frac{D_{used}}{D_{new}} \right. = {\left. \sqrt{\frac{R_{{HTR}\_{used}}}{R_{{HTR}\_{new}}}}\rightarrow D_{used} \right. = {\sqrt{\frac{R_{{HTR}\_{used}}}{R_{{HTR}\_{new}}}} \cdot D_{new}}}}}} & (4)\end{matrix}$

When the correlation between the total number of uses N_(sum) indicativeof a deterioration state in the load 3 and the electric resistance valueR_(HTR) of the load 3 is linear or can be linearly approximated, theequation (4) can be rewritten to a following equation (5).

$\begin{matrix}\left\lbrack {{equation}5} \right\rbrack &  \\{{D_{used} \equiv {\sqrt{\frac{\alpha \cdot N_{sum} \cdot R_{{HTR}\_{new}}}{R_{{HTR}\_{used}}}} \cdot D_{new}}} = {\sqrt{\alpha \cdot N_{sum}} \cdot D_{new}}} & (5)\end{matrix}$

Therefore, in a case where the correlation between the total number ofuses N_(sum) indicative of a deterioration stale in the load 3 and theelectric resistance value R_(HTR) of the load 3 is linear or can belinearly approximated, the control unit 8 can obtain the duty ratioD_(used) corresponding to the deteriorated load 3 based on the equation(5), when the total number of uses N_(sum) of the load 3 is acquired.

On the other hand, in a case where the correlation between the totalnumber of uses N_(sum) indicative of a deterioration state in the load 3and the electric resistance value R_(HTR) of the load 3 is nonlinear,when the electric resistance value R_(HTR) of the load 3 is indicated bythe function of the total number of uses N_(sum) of the load 3, theequation (4) can be rewritten to a following equation (6).

$\begin{matrix}\left\lbrack {{equation}6} \right\rbrack &  \\{D_{used} \equiv {\sqrt{\frac{R_{HTR}\left( N_{sum} \right)}{R_{HTR}(0)}} \cdot D_{new}}} & (6)\end{matrix}$

Therefore, in a case where the correlation between the total number ofuses N_(sum) indicative of a deterioration state in the load 3 and theelectric resistance value R_(HTR) of the load 3 is nonlinear, when thetotal number of uses N_(sum) of the load 3 is acquired, the control unit8 can use the equation (6) to obtain the duty ratio D_(used)corresponding to the deteriorated load 3, based on a resistance R(0) ofthe load 3 whose the total number of uses N_(sum) is zero (the load 3 isnew), a resistance R(N_(sum)) of the load 3 whose the total number ofuses is N_(sum), and the duty ratio D_(new) when the load 3 is new.

FIG. 17 is a flowchart depicting an example of processing in thepreparation phase by the control unit 8 in accordance with Example 1E.

The processing from step S1701 to step S1703 is the same as theprocessing from step S501 to step S503 in FIG. 5 .

In step S1704, the resistance value R_(HTR_used) when the load 3 isdeteriorated is input from the power source measurement unit 7 to thepreparation unit 10.

In step S1705, when the correlation between the total number of usesN_(sum) indicative of a deterioration state in the load 3 and theelectric resistance value R_(HTR) of the load 3 is linear or can belinearly approximated, the preparation unit 10 obtains the duty ratioD_(used) corresponding to the deteriorated load 3, based on the acquiredtotal number of uses N_(sum) of the load 3 and the equation (5). On theother hand, when the correlation between the total number of usesN_(sum) indicative of a deterioration state in the load 3 and theelectric resistance value R_(HTR) of the load 3 is nonlinear, thepreparation unit 10 uses the equation (6) to obtain the duty ratioD_(used) corresponding to the deteriorated load 3, based on the totalnumber of uses N_(sum) of the load 3, the resistance R(0) of the load 3when the total number of uses N_(sum) is zero (the load 3 is new), theresistance R(N_(sum)) of the load 3 when the total number of uses isN_(sum), and the duty ratio D_(new) when the load 3 is new.

In step S1706, the preparation unit 10 switches the switch 25 providedin the circuit for electrically connecting the load 3 and the powersource 4 as shown in FIG. 9 , based on the duty command value indicativeof the duty ratio D_(used), in the first sub-phase, thereby controllingthe power that is supplied to the load 3.

The processing from step S1707 to step S1709 is the same as theprocessing from step S505 to step S507 in FIG. 5 .

In Example 1E as described above, even when the load 3 is deteriorateddue to factors such as the increase in the total number of uses N_(sum)of the load 3, the power can be supplied to the load 3 so that thetemperature of the load 3 is stabilized.

In the present Example, the total number of uses N_(sum) of the load 3is used as the physical quantity indicative of the deterioration statein the load 3. However, instead of the total number of uses N_(sum), forexample, an integrated operation time of the load 3, an integrated powerconsumption of the load 3, an integrated amount of aerosol generation ofthe load 3, an electric resistance value of the load 3 at predeterminedtemperatures such as room temperature and the like may also be used.

Second Embodiment

In a second embodiment, control of changing at least one of a gain ofthe gain unit 12 and a limiter width (range) that is used in the limiterunit 14 in the feedback control that is executed in the use phase isdescribed.

In the aerosol generation device 1 configured to heat the aerosolgeneration article 9, in order to stabilize aerosols generated from theaerosol generation article 9 over time, it is necessary to graduallyshift an aerosol generation position of the aerosol generation article 9away from the vicinity of the load 3 by increasing gradually thetemperature of the load 3 or the aerosol generation article 9. Thereason is that when the heating of the aerosol generation article 9starts, aerosols are generated earlier in a position closer to the load3 in the aerosol generation article 9, taking into account heat transferfrom the load 3 to the aerosol generation article 9. That is, when anaerosol source in a position of the aerosol generation article 9 closeto the load 3 is completely atomized and the aerosol generation iscompleted, it is necessary to atomize an aerosol source distant from theload 3 so as to continuously generate aerosols from the aerosolgeneration article 9. That is, it is necessary to shift the aerosolgeneration position from a position of the aerosol generation article 9close to the load 3 to a position of the aerosol generation article 9distant from the load 3, in which the aerosol source is not completelyatomized because the heat transfer efficiency from the load 3 decreases.

As described above, the position of the aerosol generation article 9distant from the load 3 is inferior to the position of the aerosolgeneration article 9 close to the load 3, from a standpoint of heattransfer. Therefore, when it is intended to generate aerosols in theposition of the aerosol generation article 9 distant from the load 3, itis necessary for the load 3 to transfer much heat to the aerosolgeneration article 9, as compared to a case where aerosols are generatedin the position of the aerosol generation article 9 close to the load 3.In other words, when it is intended to generate aerosols in the positionof the aerosol generation article 9 distant from the load 3, it isnecessary to increase the temperature of the load 3, as compared to acase where aerosols are generated in the position of the aerosolgeneration article 9 close to the load 3.

In the second embodiment, control of stabilizing an amount of aerosolsgenerated from the aerosol generation article 9 over time by shiftingthe aerosol generation position of the aerosol generation article 9 froma position close to the load 3 to a position distant from the load isdescribed.

For example, when a first heating method in which the load 3 heats theaerosol generation article 9 from an inside thereof is used, a centralpart of the aerosol generation article 9 is the position of the aerosolgeneration article 9 close to the load 3. Also, an outer peripheral partof the aerosol generation article 9 is the position of the aerosolgeneration article 9 distant from the load 3.

For example, when a second heating method in which the load 3 heats theaerosol generation article 9 from an outside thereof is used, the outerperipheral part of the aerosol generation article 9 is the position ofthe aerosol generation article 9 close to the load 3. Also, the centralpart of the aerosol generation article 9 is the position of the aerosolgeneration article 9 distant from the load 3.

For example, when a third heating method in which the load 3 heats theaerosol generation article 9 by using induction heating (IH) is used, aposition of the aerosol generation article 9 that is in contact with orclose to a susceptor is the position of the aerosol generation article 9close to the load 3. Also, a position of the aerosol generation article9 that is not in contact with or is distant from the susceptor is theposition of the aerosol generation article 9 distant from the load 3.

However, when it is intended to gradually increase the temperature ofthe load 3 or the aerosol generation article 9 by increasing gradually atarget temperature in the feedback control, if the measured temperaturevalue exceeds temporarily the target temperature, the increase intemperature at that time is stagnant, so that the user who inhalesaerosols may feel uncomfortable.

Therefore, in the second embodiment, at least one of a gain of the gainunit 12 and the limiter width of the limiter unit 14 in the use phase isgradually increased to smoothly increase the temperature of the load 3or the aerosol generation article 9 without delay, thereby generatingstably aerosols. In the meantime, the increase in the gain of the gainunit 12 may mean adjusting a correlation between an output value and aninput value of the gain unit 12 so that an absolute value of an outputvalue to an input value input to the gain unit 12 after a gain isincreased is greater than an absolute value of the output value to theinput value input to the gain unit 12 before a gain is increased. Also,the increase in the limiter width of the limiter unit 14 may meanincreasing a maximum value that can be taken as an absolute value of anoutput value that is output from the limiter unit 14.

Comparing the control by the control unit 8 in accordance with thesecond embodiment and the control by an aerosol generation device of therelated art, the control by the control unit 8 in accordance with thesecond embodiment has a feature of performing the control while settingthe use phase end temperature constant, not the control of increasing,decreasing and again increasing the target temperature that is used inthe feedback control. That is, in the second embodiment, since thetemperature of the load 3 is lower than the use phase end temperaturethat is used in the feedback control, in most of the use phase, thetemperature of the load 3 or the aerosol generation article 9 issmoothly increased without delay over the entire use phase, so thataerosols are stably generated.

The control by the control unit 8 in accordance with the secondembodiment has a feature that it is not a control of narrowing thelimiter width of the limiter unit 14 based on the timer value t. Also,the control h the control unit 8 in accordance with the secondembodiment has a feature that it is not a control of increasing thetarget temperature based on the timer value t while setting the limiterwidth of the limiter unit 14 constant, in other words, in the control bythe control unit 8 in accordance with the second embodiment, the limiterwidth is continuously expanded or stepwise narrowed without beingnarrowed with the progress of the use phase.

When the temperature of the load 3 in the use phase is equal to orhigher than a value at which the predetermined amount or more ofaerosols can be generated from the aerosol generation article 9, forexample, the control unit 8 in accordance with the second embodiment mayacquire the temperature of the load 3 and a degree of progress of theuse phase, execute the feedback control so that the temperature of theload 3 converges to a predetermined temperature, and increase a gain inthe feedback control or an upper limit value of the power that issupplied from the power source 4 to the load 3, as the degree ofprogress progresses in the feedback control. Thereby, it is possible toincrease gradually and stably the temperature of the load 3 withoutdelay. That is, it is possible to stabilize the amount of aerosols thatare generated from the aerosol generation article 9, over the entire usephase.

Herein, the control unit 8 may increase the gain in the feedback controlby changing any element of proportional (P) control, integral (I)control and differential (D) control of PID (Proportional IntegralDifferential) control. Also, the control unit 8 may increase one gain ofproportional control, integral control and differential control or mayincrease a plurality of gains. Also, the control unit 8 may increaseboth the gain and the upper limit value of the power that is supplied tothe load 3.

The control unit 8 may be configured to increase the gain or upper limitvalue as the degree of progress progresses so that the temperature ofthe load 3 does not decrease from the start of the use phase. Thereby,it is possible to suppress the amount of aerosol generation from beingreduced.

An increase width of the gain or upper limit value with respect to aprogressing width of the degree of progress may be set constant.Thereby, it is possible to improve the stability of the feedbackcontrol.

The control unit 8 may be configured to change an increase rate of thegain or upper limit value to the progressing width of the degree ofprogress. Thereby, it is possible to generate an appropriate amount ofaerosols according to the degree of progress.

The control unit 8 may be configured to increase the increase rate asthe degree of progress progresses. Thereby, it is possible to suppressthe amount of aerosol generation from being reduced. Also, it ispossible to shorten a time period during which the load 3 is at hightemperatures, so that it is possible to suppress the load 3 and theaerosol generation device 1 from being overheated, thereby improving thedurability of the load 3 and the aerosol generation device 1. Also,since the time period during which the load 3 is at high temperatures isshort, it is possible to simplify an adiabatic structure of the aerosolgeneration device 1. In particular, when the aerosol generation device 1adopts the second heating method, it is possible to simplify theadiabatic structure.

The control unit 8 may be configured to reduce the increase rate as thedegree of progress progresses. Thereby, it is possible to prolong a timeperiod during which the load 3 is at high temperatures, so that it ispossible to suppress the amount of aerosol generation from beingreduced. Since it is possible to prolong the time period during whichthe load 3 is at high temperatures, it is possible to increase theamount of aerosols that are generated from one aerosol generationarticle 9. Also, since a time period during which the gain or upperlimit value increases is long, it is possible to promptly recover thedecrease in temperature (for example, temperature drop) due to theinhalation of aerosols by the user, thereby compensating for thetemperature of the load 3. That is, it is possible to stabilize theamount of aerosols that are generated from one aerosol generationarticle 9, over the entire use phase.

The control unit 8 may be configured to determine the gain or upperlimit value corresponding to the degree of progress, based on a firstrelation (correlation) that the gain or upper limit value increases asthe degree of progress progresses, and to change the first relation,based on time-series change in the degree of progress. Thereby, it ispossible to change a degree of increase in the gain or upper limitvalue, in accordance with a progressing degree of the degree ofprogress, and to supply an appropriate amount of power to the load 3 inaccordance with an actual progressing degree, so that it is possible tostabilize the amount of aerosol generation.

The control unit 8 may be configured to change the first relation sothat the gain or upper limit value increases as the degree of progressprogresses. In this case, since the gain or upper limit value is notdecreased, it is possible to suppress the amount of aerosol generationfrom being reduced.

When the degree of progress is delayed in comparison with apredetermined degree of progress, the control unit 8 may change thefirst relation so that the increase width of the gain or upper limitvalue corresponding to the progressing width of the degree of progressincreases, and may set the temperature of the load 3 as the degree ofprogress. Thereby, as the increase in temperature of the load 3 isfurther delayed, it is possible to easily increase the temperature ofthe load 3, so that it is possible to suppress the amount of aerosolgeneration from being reduced.

When the degree of progress is further progressed in comparison with apredetermined degree of progress, the control unit 8 may change thefirst relation so that the increase width of the gain or upper limitvalue corresponding to the progressing width of the degree of progressdecreases, and may set the temperature of the load 3 as the degree ofprogress. Thereby, as the increase in temperature of the load 3 isfurther progressed, it is possible to make it difficult for thetemperature of the load 3 to increase, so that it is possible tosuppress the amount of aerosol generation from increasing.

When the degree of progress is delayed in comparison with apredetermined degree of progress, the control unit 8 may change thefirst relation so that the increase width of the gain or upper limitvalue corresponding to the progressing width of the degree of progressdecreases, and may set the degree of progress to include at least one ofa number of times of aerosol inhalation, an amount of aerosolinhalation, and an amount of aerosol generation. For example, whenaerosol inhalation is delayed in comparison with a predetermined degreeof progress, it is believed that the aerosol source near the load 3 isnot depleted. In this case, when the increase width of the gain or upperlimit value is decreased, it is possible to effectively use the aerosolsource in the aerosol generation article 9.

When the degree of progress is further progressed in comparison with apredetermined degree of progress, the control unit 8 may change thefirst relation so that the increase width of the gain or upper limitvalue corresponding to the progressing width of the degree of progressincreases, and may set the degree of progress to include at least one ofa number of times of aerosol inhalation, an amount of aerosolinhalation, and an amount of aerosol generation. For example, when thedegree of progress is further progressed in comparison with apredetermined degree of progress, it is believed that the aerosolgeneration position of the aerosol generation article 9 is shifted to aposition distant from the load 3 than expected. Even in this case, whenthe increase width of the gain or upper limit value is increased, it ispossible to positively generate aerosols from the aerosol generationposition distant from the load 3.

The control unit 8 may be configured to temporarily change the firstrelation or to change a part of the first relation. In this case, sincethe increase width of the gain or upper limit value is temporarilychanged and is then returned to the original increase width, it ispossible to improve the stability of the control.

The control unit 8 may be configured to change an entire part of thefirst relation after the latest degree of progress acquired by thecontrol unit 8. In this case, since the increase width of the gain orupper limit value is entirely changed, it is possible to reduce apossibility that it will be necessary to again perform the change.

In the meantime, the control unit 8 may be configured to change theentire first relation including the degree of progress more past thanthe latest degree of progress.

The control unit 8 may be configured to change a part of the firstrelation after the latest degree of progress acquired by the controlunit 8, and may set a relation between the degree of progress and thegain or upper limit value at the end of the use phase to be the samebefore and after the change of the first relation. In this case, sincethe gain or upper limit value does not change at the end of the usephase, it is possible to suppress the amount of power supplied to theload 3 from largely changing, thereby improving the stability of thecontrol.

The predetermined temperature may be a temperature of the load 3 that isnecessary to generate aerosols from the aerosol source or theaerosol-forming substrate 9 a included in the mounted aerosol generationarticle 9 and located in a position most distant from the load 3.Thereby, it is possible to effectively generate aerosols from theaerosol generation article 9.

When the temperature of the load 3 reaches the predeterminedtemperature, the control unit 8 may end the use phase. Thereby, it ispossible to suppress the aerosol generation article 9 from beingoverheated.

When the temperature of the load 3 reaches the predetermined temperatureor when the degree of progress reaches the predetermined thresholdvalue, the control unit 8 may end the use phase. Thereby, it is possibleto end the feedback control more safely and securely.

When the temperature of the load 3 reaches the predetermined temperatureand the degree of progress reaches a predetermined threshold value, thecontrol unit 8 may end the use phase. Thereby, it is possible togenerate more aerosols from the aerosol generation article 9 whilestrictly setting the end condition in an appropriate range.

The control unit 8 may be configured to increase the gain or upper limitvalue so that a time period in which the temperature of the load 3 islower than the predetermined temperature is longer than a time period inwhich the temperature of the load 3 is equal to or higher than thepredetermined temperature, in the use phase. In this case, since thetime period in which the temperature of the load 3 is not near thepredetermined temperature is longer than the time period in which thetemperature of the load 3 is near the predetermined temperature, it ispossible to suppress the increase in amount of aerosol generation.

As the degree of progress, elapse time of the use phase, the number oftimes of aerosol inhalation, the amount of aerosol inhalation, theamount of aerosol generation or the temperature of the load 3 can beused according to the control of the control unit 8.

The control unit 8 in accordance with the second embodiment isconfigured to increase the gain in the feedback control or the upperlimit value of the power that is supplied from the power source 4 to theload so that the temperature of the load 3 gradually approaches from afirst temperature, at which the predetermined amount or more of aerosolscan be generated from the aerosol source or the aerosol-formingsubstrate 9 a included in the aerosol generation article 9 and locatedin a closest position to the load 3, to a second temperature at whichthe predetermined amount or more of aerosols can be generated from theaerosol source or the aerosol-forming substrate 9 a included in theaerosol generation article 9 and located in a position most distant fromthe load 3, for example. Thereby, the control unit 8 can effectivelyperform the aerosol generation over the entire range from a positionclose to the load 3 to a position of the aerosol generation article 9distant from the load 3 by the feedback control.

In the case of the use phase where the temperature of the load 3 isequal to or greater than a value at Which the predetermined amount ormore of aerosols can be generated from the aerosol generation article 9,for example, the control unit 8 in accordance with the second embodimentmay acquire the temperature of the load 3 and the degree of progress ofthe use phase, determine the power that is supplied from the powersource 4 to the load 3, based on a difference between the temperature ofthe load 3 and the predetermined temperature, and execute the feedbackcontrol so that a change rate of the supply amount of power with theprogressing of the use phase is greater than a change rate of thepredetermined temperature with the progressing of the use phase. In themeantime, the change rate may also include a state in which the changerate is zero, i.e., there is no change. Thereby, it is possible toincrease gradually and stably the temperature of the load 3 withoutdelay.

In the case of the use phase where the temperature of the load 3 isequal to or greater than a value at which the predetermined amount ormore of aerosols can be generated from the aerosol generation article 9,for example, the control unit 8 in accordance with the second embodimentmay acquire the temperature of the load 3 and the degree of progress ofthe use phase, determine the power that is supplied from the powersource 4 to the load 3, based on a difference between the temperature ofthe load 3 and the predetermined temperature, and execute the feedbackcontrol so that a value obtained by subtracting the temperature of theload 3 from the predetermined temperature decreases with the progressingof the use phase and the supply amount of power that is supplied fromthe power source 4 to the load 3 increases with the progressing of theuse phase. Thereby, it is possible to increase gradually and stably thetemperature of the load 3 without delay.

The diverse controls by the control unit 8 may also be implemented asthe control unit 8 executes the program.

Regarding the second embodiment, specific control examples are furtherdescribed in following embodiments 2A to 2F.

Example 2A

FIG. 18 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 2A.

The limiter change unit 13 of the control unit 8 keeps the firstrelation in Which an input parameter including at least one of thetinier value t, the measured temperature value of the load 3 and a puffprofile and the limiter width of the limiter unit 14 are associated witheach other. The timer value t, the measured temperature value of theload 3, and the puff profile are examples of the value indicative of thedegree of progress of the use phase. Instead, other physical quantitiesor variables that tend to increase according to the degree of progressof the use phase may also be used.

In Example 2A, a case where the timer value t, the measured temperaturevalue and the puff profile are used as the input parameter is described.However, a part of the timer value t, the measured temperature value andthe puff profile may also be used as the input parameter.

The association between the input parameter and the limiter width may bemanaged by a table or a data structure such as a list structure and afunction relating to the input parameter and the limiter width may beused. The same applies to a variety of associations described later.

In the use phase, the control unit 8 inputs the timer value t from thetimer 5, and inputs the measured temperature value indicative of thetemperature of the load 3 from the temperature measurement unit 6.

The control unit 8 detects the user's inhalation, based on an outputvalue of a sensor configured to detect a physical quantity that varieswith the user's inhalation, such as a flow rate sensor, a flow velocitysensor and a pressure sensor provided in the aerosol generation device1, for example, and generates a puff profile indicative of an inhalationstate such as the number of times of user's time-series inhalation or anamount of inhalation, for example.

The control unit 8 includes the limiter change unit 13, the differentialunit 11, the gain unit 12, and the limiter unit 14.

The limiter change unit 13 determines an increase width of the limiterwidth that is used in the limiter unit 14, based on the input parameter,and gradually expands the limiter width as the use phase progresses.

In Example 2A, the limiter change unit 13 may not narrow the limiterwidth, for example. In other words, when changing the limiter width, thelimiter change unit 13 may only expand the limiter width. In the below,also in Examples 2B to 2F of the second embodiment, the limiter widththat is used in the limiter change unit 13 may not be narrowed.

More specifically, the limiter change unit 13 changes the limiter widthof the limiter unit 14 so that a width between a limiter maximum valueand a limiter minimum value is expanded, as the timer value t increases.

The differential unit 11 obtains a difference between the measuredtemperature value measured by the temperature measurement unit 6 and theuse phase end temperature. In Example 2A, it is assumed that the usephase end temperature is a fixed value and is a value that thetemperature of the load 3 should reach at the end of the use phase bythe feedback control, for example.

The gain unit 12 obtains, based on the difference between the measuredtemperature value and the use phase end temperature, a duty ratio atwhich the difference is removed or reduced. In other words, the gainunit 12 outputs, to the limiter unit 14, a duty ratio having acorrelation of a difference between the measured temperature value andthe use phase end temperature and the duty ratio and corresponding to adifference between the input measured temperature value and the usephase end temperature.

The limiter unit 14 controls so that the duty ratio obtained by the gainunit 12 is included in the limiter width. Specifically, when the dutyratio obtained by the gain unit 12 exceeds the maximum value of thelimiter width obtained by the limiter change unit 13, the limiter unit14 sets the duty ratio as the maximum value of the limiter width, andwhen the obtained duty ratio falls below the minimum value of thelimiter width obtained by the limiter change unit 13, the limiter unit14 limits the duty ratio to the minimum value of the limiter width. Thelimiter unit 14 outputs, as a result of the limiter processing, a dutyoperation value indicative of the duty ratio included in the limiterwidth to the comparison unit 15 shown in FIG. 3 , for example. The dutyoperation value is a value obtained as a result of the feedback controlby the control unit 8.

FIG. 19 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 2A.

In step S1901, the control unit 8 inputs the timer value t from thetimer 5.

In step S1902, the control unit 8 determines whether the timer value tis equal to or greater than time t_(thre) indicative of an end of theuse phase.

When it is determined that the tinier value t is equal to or greaterthan time t_(thre) (a determination result in step S1902 isaffirmative), the control unit 8 stops the supply of power to the load3, and ends the use phase.

When it is determined that the timer value t is not equal to or greaterthan time t_(thre) (a determination result in step S1902 is negative),the differential unit 11 of the control unit 8 obtains a differenceΔT_(HTR) between the use phase end temperature of the load 3 and themeasured temperature value input from the temperature measurement unit6, in step S1903.

In step S1904, the limiter change unit 13 of the control unit 8determines the increase width of the limiter width that is used in thelimiter unit 14, based on at least one of the timer value t, themeasured temperature value and the puff profile, and changes the limiterwidth.

In step S1905, the gain unit 12 of the control unit 8 obtains the dutyratio (the duty operation value) D_(cmd), based on the differenceΔT_(HTR). When a correlation between the input value and the outputvalue in the gain unit 12 is denoted as a function K, the processing ofthe gain unit 12 can be expressed by D_(cmd)=K (ΔT_(HTR)). Inparticular, in a case where the correlation between the input value andthe output value in the gain unit 12 is linear, when a gain coefficientthat is a gradient of the correlation is denoted as K, the processing ofthe gain unit 12 can be expressed by D_(cmd)=K×ΔT_(HTR).

In step S1906, the limiter unit 14 of the control unit 8 performs thelimiter processing so that the duty ratio D_(cmd) obtained by the gainunit 12 falls in the limiter width of the limiter unit 14, therebyobtaining a limiter processed duty ratio D_(cmdd).

In step S1907, the control unit 8 controls the power that is supplied tothe load 3, based on a duty command value indicative of the duty ratioD_(cmdd), and then the processing returns to step S1901. In themeantime, the duty ratio D_(cmdd) may also be applied to the switch 25provided between the power source 4 and the load 3 or to the DC/DCconverter provided between the power source 4 and the load 3.

In the above processing, the sequence of step S1904 and step S1905 maybe interchanged.

In the control that is executed by the control unit 8 in accordance withExample 2A, the limiter width that is used in the limiter unit 14 ischanged to be gradually expanded each time the use phase progresses, andthe temperature of the load 3 is controlled based on the duty ratioD_(cmdd) in the limiter width. Thereby, it is possible to smoothlyincrease the temperature of the load 3 or the aerosol generation article9 without delay, so that it is possible to stably generate aerosols.

Example 2B

In Example 2B, control in which the limiter change unit 13 determinesthe increase width of the limiter width, based on a determination as towhether a heat capacity of the aerosol generation article 9 is greaterthan expected with the time-series progressing of the use phase, andchanges the limiter width is described.

In Example 2B, the heat capacity of the aerosol generation article 9 mayalso be strictly obtained from a mass and a specific heat of the aerosolgeneration article 9. As another example, the heat capacity of theaerosol generation article 9 may be treated as a physical quantity thatdepends on compositions or structures of the aerosol-forming substrate 9a, the flavor source and the aerosol source provided in the aerosolgeneration article 9 and shows a larger value as the remaining amountsof the aerosol generation article 9, the flavor source and the aerosolsource are larger. That is, when the aerosol generation article 9 isheated by the load 3, at least a part of the aerosol-forming substrate 9a and the flavor source or the aerosol source is consumed, so that theheat capacity of the aerosol generation article 9 tends to decrease withthe progressing of the use phase. In other words, it is assumed that theheat capacity of the aerosol generation article 9 indicates an amount ofaerosols that can be generated by the aerosol generation article 9, aremaining amount of aerosols that can be inhaled by the user of theaerosol generation device 1, the number of times of remaining inhalationor an amount of heat that can be applied to the aerosol generationarticle 9 by the aerosol generation device 1. In the meantime, it shouldbe noted that, even when an amount of aerosols that can be generated bythe aerosol generation article 9, a remaining amount of aerosols thatcan be inhaled by the user of the aerosol generation device 1 or thenumber of times of remaining inhalation is zero, the heat capacity ofthe aerosol generation article 9 is not zero.

The control unit 8 and/or the limiter change unit 13 in accordance withExample 2B may determine whether the heat capacity of the aerosolgeneration article 9 is larger than expected with the time-seriesprogressing of the use phase, based on the measured temperature value orthe puff profile. As an example, the control unit 8 and/or the limiterchange unit 13 in accordance with Example 2B stores in advance idealtime-series data about the temperature of the load 3 or the aerosolgeneration article 9 in the use phase, the number of times of inhalationby the user of the aerosol generation device 1 in the use phase or anintegrated value of the amount of inhalation. By comparing the idealtime-series data and the measured temperature value or the puff profile,it may be determined whether the heat capacity of the aerosol generationarticle 9 is greater than expected with the time-series progressing ofthe use phase.

Specifically, when the measured temperature value is delayed withrespect to the ideal time-series data, the control unit 8 and/or thelimiter change unit 13 may determine that the heat capacity of theaerosol generation article 9 is greater than expected. On the otherhand, when the measured temperature value is progressing with respect tothe ideal time-series data, the control unit 8 and/or the limiter changeunit 13 may determine that the heat capacity of the aerosol generationarticle 9 is less than expected.

In other words, in a state where the heat capacity of the aerosolgeneration article 9 is large, it is estimated that the measuredtemperature value is small. On the other hand, in a state where the heatcapacity of the aerosol generation article 9 is not large (is small), itis estimated that the measured temperature value is large.

When the measured temperature value is small, the limiter change unit 13expands the increase width of the limiter width.

When the measured temperature value is large, the limiter change unit 13narrows the increase width of the limiter width.

In the meantime, when the puff profile is delayed with respect to theideal time-series data, the control unit 8 and/or the limiter changeunit 13 may determine that the heat capacity of the aerosol generationarticle 9 is larger than expected. In this case, as can be clearly seenfrom the delay of the puff profile, the user does not inhale the aerosolgeneration device 1 more than expected. Therefore, it should be notedthat it is less necessary to expand the increase width of the limiterwidth so as to increase or keep the amount of aerosols that aregenerated from the aerosol generation article 9 by expanding theincrease width of the limiter width.

Also, when the puff profile progresses with respect to the idealtime-series data, the control unit 8 and/or the limiter change unit 13may determine that the heat capacity of the aerosol generation article 9is smaller than expected. In this case, as can be clearly seen from theprogressing of the puff profile, the user inhales the aerosol generationdevice 1 more than expected, Therefore, it should be noted that it isnecessary to positively expand the increase width of the limiter widthso as to increase or keep the amount of aerosols that are generated fromthe aerosol generation article 9 by expanding the increase width of thelimiter width.

When the puff profile is delayed, the limiter change unit 13 narrows theincrease width of the limiter width.

When the puff profile progresses, the limiter change unit 13 expands theincrease width of the limiter width.

In the meantime, as described above, even when any of the measuredtemperature value and the puff profile is used for the degree ofprogress of the use phase, in Example 2B, the limiter change unit 13does not narrow the limiter width with the progressing of the use phase.

FIG. 20 depicts an example of changing the limiter width in the limiterchange unit 13 in accordance with Example 2B. In FIG. 20 , theupward-sloping broken line indicates the increase width of the limiterwidth before change. In a first change example of the limiter widthshown with the dotted line in FIG. 20 , the limiter change unit 13expands or narrows temporarily the increase width of the limiter width,based on the input parameter, and then returns the increase width of thelimiter width to the state before change shown with the upward-slopingbroken line in FIG. 20 . In the meantime, it should be noted that thelimiter change unit 13 does not output the increase width of the limiterwidth before change shown with the broken line, in an area in which thelimiter width shown with the dotted line in the first change example ofthe limiter width is applied.

In a second change example of the limiter width shown with the solidline in FIG. 20 , the limiter change unit 13 expands or narrows theincrease width of the limiter width, based on the input parameter, andthen maintains the change of the limiter width by the increase width. Inother words, in the second change example, intercepts of the functionincluding the limiter width and the input parameter are uniformlychanged.

In a third change example of the limiter width shown with thedashed-dotted line in FIG. 20 , the limiter change unit 13 expands ornarrows the increase width of the limiter width, based on the inputparameter, and then changes the increase width of the limiter width soas to be a limiter width expected at the end of the use phase.

FIG. 21 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 2B. In FIG. 21 ,a case where the increase width of the limiter width is determined basedon the puff profile or the measured temperature value and the limiterwidth is changed based on the determined increase width is exemplified.

The processing of step S2101 and step S2102 is the same as theprocessing of step S1901 and step S1902 in FIG. 19 .

When it is determined in step S2102 that the tinier value t is not equalto or greater than time t_(thre) (a determination result is negative),the puff profile or the measured temperature value is input to thelimiter change unit 13 in step S2103, for example.

In step S2104, the limiter change unit 13 determines whether the inputpuff profile or measured temperature value is within an assumed range(within a predetermined range). In the meantime, the description “theinput puff profile or measured temperature value is within an assumedrange” indicates that there is no deviation between the idealtime-series data and the input puff profile or measured temperaturevalue or there is a slight deviation.

When it is determined that the puff profile or the measured temperaturevalue is within the assumed range (a determination result in step S2104is affirmative), the processing proceeds to step S2106.

When it is determined that the puff profile or the measured temperaturevalue is not within the assumed range (a determination result in stepS2104 is negative), the limiter change unit 13 changes the increasewidth of the limiter width in step S2105, and the processing proceeds tostep S2106.

The processing from step S2106 to step S2110 is the same as theprocessing from step S1903 to step S1907 in FIG. 19 .

The operational effects of Example 2B described above are described.

The user's aerosol inhalation pace by the aerosol generation device 1 isdifferent depending on users. Also, there is an inevitable product errorbetween the aerosol generation device 1 and/or the aerosol generationarticle 9. In Example 2B, in order to resolve/absorb the error based onthe user's aerosol inhalation pace and the product error, the increasewidth of the limiter width that is used in the limiter unit 14 ischanged based on the degree of progress of the use phase. Thereby, it ispossible to stabilize the control on the aerosol generation.

Example 2C

It is possible to suppress the aerosol generation article 9 from beingoverheated by suppressing the time period in which the load 3 is at hightemperatures, for example.

In the meantime, it is possible to promote the aerosol generation in aposition of the aerosol generation article 9 distant from the load 3 byprolonging the time period in which the load 3 is at high temperatures.

Therefore, in Example 2C, it is described that the increase width of thelimiter width is expanded or narrowed and the temperature of the load 3is controlled, so as to suppress the aerosol generation article 9 frombeing overheated or to promote the aerosol generation.

In order to stably generate aerosols over the entire use phase, it isnecessary to generate aerosols from a position of the aerosol generationarticle 9 distant from the load 3 over time from the start of aerosolgeneration.

As described above, when a position of the aerosol generation article 9distant from the load 3 is subjected to a temperature suitable foraerosol generation, it is necessary to put the load 3 in highertemperatures than at the start of aerosol generation.

The control unit 8 performs control so that the load 3 is at the usephase end temperature at the end of the use phase. However, it ispossible to suppress the load 3 from being overheated as a time periodin which the load is maintained at the use phase end temperature isshorter.

In the meantime, there is a case where the load 3 is preferably at hightemperatures for a long time so as to generate a sufficient amount ofaerosols even in a position distant from the load 3.

FIG. 22 is a graph depicting an example of a change in the limiter widththat is used in the limiter unit 14 and a state of increase intemperature of the load 3. In FIG. 22 , the horizontal axis indicatesthe timer value t. The vertical axis indicates the temperature or thelimiter width.

A line L_(28A) indicates that the smaller the timer value (time) t is,the smaller the increase width of the limiter width is, and the largerthe timer value t is, the larger the increase width of the limiter widthis. A change in temperature corresponding to the line L_(28A) is a lineL_(28B). The line L_(28B) shows that an increase in temperature of theload 3 is slow and the temperature of the load 3 increases as it comesclose to the end of the use phase. The limiter change unit 13 canprevent an overheated state of the load 3 by changing the increase widthof the limiter width so as to follow the line L_(28A) and the lineL_(28B).

In the meantime, a line L_(28C) indicates that the smaller the tiniervalue (time) t is, the larger the increase width of the limiter widthis, and the larger the timer value t is, the smaller the increase widthof the limiter width is. A change in temperature corresponding to theline L_(28C) is a line L_(28D). The line USD shows that an increase intemperature of the load 3 is fast and the time period in which thetemperature of the load 3 is maintained near the use phase endtemperature is prolonged. The limiter change unit 13 can generate asufficient amount of aerosols from a position of the aerosol generationarticle 9 distant from the load 3 by changing the increase width of thelimiter width so as to follow the line L_(28C) and the line L_(28D).

FIG. 23 is a graph depicting an example of a change in the limiter widthin accordance with Example 2C.

The limiter change unit 13 changes the limiter width, based on the timervalue tin principle, for example, and determines the increase width ofthe limiter width at the time of changing the limiter width, based on atleast one of the puff profile and the measured temperature value.

A line L_(29A) indicates an expanded state of the increase width of thelimiter width, and a line L_(29B) indicates a narrowed state of theincrease width of the limiter width.

In Example 2C described above, the increase width of the limiter widthis changed according to the degree of progress, thereby suppressing theload 3 from being overheated.

Also, in Example 2C, it is possible to effectively generate aerosols inthe position of the aerosol generation article 9 distant from the load3.

Example 2D

In Example 2A to Example 2C, the limiter change unit 13 changes thelimiter width that is used in the limiter unit 14.

In contrast, in Example 2D, the gain of the gain unit 12 is changedbased on the input parameter including at least one of the timer valuet, the temperature of the load 3 and the puff profile.

FIG. 24 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 2D.

A gain change unit 17 provided in the control unit 8 in accordance withExample 2D changes a gain that is used in the gain unit 12, based on theinput parameter including at least one of the timer value t, themeasured temperature value and the puff profile. The change of the gainincludes a change of a control characteristic, a change of a gainfunction and a change of a value included in a gain function, forexample. The gain function has a second relation in which a differencebetween the use phase end temperature and the measured temperature valueand a duty ratio corresponding to the difference are associated witheach other, for example.

When the gain change unit 17 changes a gain that is used in the gainunit 12, based on the input parameter, a duty ratio that is obtainedbased on the difference input from the differential unit 11 can bechanged.

FIG. 25 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 2D.

The processing from step S2501 to step S2503 is the same as theprocessing from step S1901 to step S1903 in FIG. 19 .

In step S2504, the gain change unit 17 of the control unit 8 changes again of the gain unit 12, based on the input parameter.

The processing from step S2505 to step S2507 is the same as theprocessing from step S1905 to step S1907 in FIG. 19 .

In Example 2D as described above, the gain of the gain unit 12 otherthan the limiter width of the limiter unit 14 is changed to stabilizethe control on the aerosol generation.

Example 2E

In Example 2E, an end condition of the use phase is that the measuredtemperature value is equal to or greater than a predeterminedtemperature, and control of ending the use phase when the measuredtemperature value is equal to or greater than the predeterminedtemperature is described. Herein, for example, the predeterminedtemperature may be equal to or higher than the use phase end temperatureof the load 3. The predetermined temperature may be the temperature ofthe load 3 that is necessary to generate aerosols from the aerosolsource or the aerosol-forming substrate 9 a included in the aerosolgeneration article 9 and located in the position most distant from load3, as described above, for example.

FIG. 26 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 2E.

The processing from step S2601 to step S2607 is the same as theprocessing from step S1901 to step S1907 in FIG. 19 .

When it is determined in step S2602 that the timer value t is equal toor greater than time t_(thre) (a determination result is affirmative),the control unit 8 determines in step S2608 whether the measuredtemperature value is equal to or greater than the predeterminedtemperature.

When it is determined that the measured temperature value is equal to orgreater than the predetermined temperature (a determination result instep S2608 is affirmative), the control unit 8 stops the supply of powerto the load 3 and ends the use phase.

When it is determined that the measured temperature value is not equalto or greater than the predetermined temperature (a determination resultin step S2608 is negative), the control unit S repeats step S2608.

In Example 2E as described above, when the measured temperature value isequal to or greater than the predetermined temperature, the use phase isended.

Particularly, in Example 2E, as the end condition of the use phase, thecondition where the timer value t is equal to or greater than timet_(thre) and the measured temperature value is equal to or greater thanthe predetermined temperature is used.

Thereby, the end condition is strictly set, so that it is possible togenerate more aerosols from the aerosol generation article 9 whilesuppressing the aerosol generation article 9 from being overheated.

In the meantime, as the end condition of the use phase, the conditionwhere the timer value t is equal to or greater than time t_(thre) mayalso be used, as described in Examples 2A to 2C.

Also, as the end condition of the use phase, any one of the conditionwhere the timer value t is equal to or greater than time L_(thre) andthe condition where the measured temperature value is equal to orgreater than the predetermined temperature may also be used. Thereby, itis possible to end the use phase safely and securely, therebysuppressing the aerosol generation article 9 from being overheated.

Example 2F

In Example 2F, features of the control by the control unit 8 in the usephase in the second embodiment are described.

FIG. 27 is a graph depicting an example of comparison between a usephase end temperature in accordance with the second embodiment and atarget temperature in accordance with an aerosol generation device ofthe related art. In FIG. 27 , the horizontal axis indicates the timervalue t. The vertical axis indicates the temperature or the power. Thepower may also be indicated by the duty ratio, for example.

For example, in the aerosol generation device of the related art, asshown with a line L_(33A), control of increasing the target temperatureof the load 3 and/or the aerosol generation article 9 over time isexecuted.

In contrast, in the control that is executed by the control unit 8 ofthe second embodiment, as shown with a line L_(33B), the use phase endtemperature is constant, i.e., does not change. In the secondembodiment, the increase width of the power that is supplied to the load3 stepwise increases, as shown with a line L_(33C).

In other words, in the control that is executed by the control unit 8 ofthe second embodiment, a rate of change in the power that is supplied tothe load 3 with the progressing of the use phase is greater than a rateof change in the use phase end temperature with the progressing of theuse phase.

FIG. 28 is a graph depicting an example of comparison of a differencebetween the use phase end temperature and the measured temperature valuein accordance with the second embodiment and a difference between thetarget temperature and the measured temperature value in accordance withthe aerosol generation device of the related art. In FIG. 28 , thehorizontal axis indicates the timer value t. The vertical axis indicatesthe difference or the power.

For example, in the aerosol generation device of the related art, asshown with a line L_(34A), the temperature of the load 3 is immediatelycontrolled so that a value obtained by subtracting the measuredtemperature value from the target temperature reduces.

In contrast, in the control that is executed by the control unit 8 ofthe second embodiment, as shown with a line L_(34B), a value obtained bysubtracting the measured temperature value from the use phase endtemperature reduces as the timer value t increases, i.e., over time.

In this way, in the control that is executed by the control unit 8 ofthe second embodiment, the value obtained by subtracting the measuredtemperature value from the use phase end temperature reduces with theprogressing of the use phase and the power that is supplied from thepower source 4 to the load 3 increases with the progressing of the usephase at the same time.

Third Embodiment

In a third embodiment, a case where the aerosol generation device 1executes different controls in multiple phases and the multiple phasesincludes a first phase that is first executed and a second phase that isexecuted later than the first phase is described.

The aerosol generation device 1 in accordance with the third embodimentincludes the load 3 configured to heat the aerosol generation article 9by using the power that is supplied from the power source 4, and thecontrol unit 8 configured to control the power that is supplied from thepower source 4 to the load 3 in multiple phases where different controlmodes are executed. The control modes are different in the multiplephases relating to the heating of the aerosol generation article 9, sothat a control mode having a characteristic suitable for a phase can beused and the temperatures of the load 3 and the aerosol generationarticle 9, which is heated by the load 3, can be further highlycontrolled. Therefore, even with the aerosol generation article 9 havinga complicated structure, it is possible to highly control aerosols to begenerated.

As described in the first and second embodiments, for example, thecontrol unit 8 may be configured to execute a first feed-forward controlin the first phase and to execute at least feedback control of a secondfeed-forward control and the feedback control in the second phase. Inthis way, the control by the control unit 8 is shifted from theteed-forward control to the feedback control, so that it is possible torealize the high-speed temperature increase of the load 3 and theaerosol generation article 9 by the feed-forward control and the stableaerosol generation by the feedback control at the same time, which areconflicting effects.

The number of the control modes that are used in the second phase may belarger than the number of the control modes that are used in the firstphase. Thereby, after the shift from the first phase to the secondphase, it is possible to realize the stable aerosol generation by usingthe plurality of control modes.

An execution time of the first phase may be shorter than an executiontime of the second phase where the rate of temperature increase of theload 3 is lower than in the first phase. Thereby, the execution time isshortened in the phase where the temperature increase of the load 3 andthe aerosol generation article 9 is faster, so that it is possible toearly generate aerosols.

The execution time of the first phase may be shorter than the executiontime of the second phase where the temperature of the load or an averagetemperature of the load is higher than in the first phase. Thereby, theexecution time is shortened in the phase where the temperatures of theload 3 and the aerosol generation article 9 or the average temperaturesof the load 3 and the aerosol generation article 9 are lower, so that itis possible to early generate aerosols.

An amount of power that is supplied from the power source 4 to the load3 in the first phase may be smaller than an amount of power that issupplied from the power source 4 to the load 3 in the second phase wherethe rate of temperature increase of the load 3 is lower than in thefirst phase. Thereby, an amount of power to be consumed is reduced inthe phase where the rate of temperature increase of the load 3 and theaerosol generation article 9 is higher, so that it is possible toimprove use efficiency of the power source 4 for aerosol generation.

The amount of power that is supplied from the power source 4 to the load3 in the first phase may be smaller than the amount of power that issupplied from the power source 4 to the load 3 in the second phase wherethe temperature of the load or an average temperature of the load ishigher than in the first phase. Thereby, an amount of power to beconsumed is reduced in the phase where the temperatures of the load 3and the aerosol generation article 9 or the average temperatures of theload 3 and the aerosol generation article 9 are lower, so that it ispossible to improve the use efficiency of the power source 4 for aerosolgeneration.

The power that is supplied from the power source 4 to the load 3 in thefirst phase may be more than the power that is supplied from the powersource 4 to the load 3 in the second phase where the rate of temperatureincrease of the load 3 is lower than in the first phase. In this way,the power that is consumed in the first phase is more than the powerthat is consumed in the second phase, so that it is possible to quicklygenerate aerosols in the first phase, to stably generate a preferableamount of aerosols in the second phase and to suppress the power that isconsumed in the second phase.

The power that is supplied from the power source 4 to the load 3 in thefirst phase may be more than the power that is supplied from the powersource 4 to the load 3 in the second phase where the temperature of theload or an average temperature of the load is higher than in the firstphase. In this way, the power that is consumed in the first phase ismore than the power that is consumed in the second phase, so that it ispossible to quickly generate aerosols in the first phase, to stablygenerate a preferable amount of aerosols in the second phase and tosuppress the power that is consumed in the second phase.

The rate of temperature increase of the load 3 in the second phase maybe lower than the rate of temperature increase of the load 3 in thefirst phase, and the number of conditions of ending the second phasewhen satisfied may be larger than the number of conditions of ending thefirst phase when satisfied. Thereby, it is possible to stably end theaerosol generation.

The rate of temperature increase of the load 3 in the second phase maybe lower than the rate of temperature increase of the load 3 in thefirst phase, and the number of end conditions that should be satisfiedso as to end the second phase may be larger than the number of endconditions that should be satisfied so as to end the first phase.Thereby, since the end of the second phase is more carefully determined,it is possible to sufficiently secure the time during which the secondphase is executed, thereby generating more aerosols from the aerosolgeneration article 9.

The temperature or average temperature of the load 3 in the second phasemay be higher than the temperature or average temperature of the load 3in the first phase, and the number of conditions of ending the secondphase when satisfied may be larger than the number of conditions ofending the first phase when satisfied. Thereby, it is possible to stablyend the aerosol generation.

The temperature or average temperature of the load 3 in the second phasemay be higher than the temperature or average temperature of the load 3in the first phase, and the number of end conditions that should besatisfied so as to end the second phase may be larger than the number ofend conditions that should be satisfied so as to end the first phase.Thereby, since the end of the second phase is more carefully determined,it is possible to sufficiently secure the time during which the secondphase is executed, thereby generating more aerosols from the aerosolgeneration article 9.

The multiple phases include the first phase, and the second phase wherethe rate of temperature increase of the load 3 is lower than in thefirst phase, and the number of variables that are acquired by thecontrol unit 8 before execution of the first phase or before theincrease in temperature of the load 3 in the first phase and are used inthe control on the power that is supplied from the power source 4 to theload 3 in the first phase may be larger than the number of variablesthat are acquired by the control unit 8 before execution of the secondphase or before the increase in temperature of the load 3 in the secondphase and are used in the control on the power that is supplied from thepower source 4 to the load 3 in the second phase. Thereby, environmentsettings at the start of the phase increase in the phase where the rateof temperature increase is higher, so that it is possible to increasethe temperatures of the load 3 and the aerosol generation article 9 morestably and faster.

The multiple phases includes a phase where the rate of temperatureincrease of the load 3 is the lowest, and the control unit 8 may notacquire variables that are used in the control on the power that issupplied from the power source 4 to the load 3 in the lowest phasebefore execution of the lowest phase or before the increase intemperature of the load 3 in the lowest phase or may not execute thecontrol on the power that is supplied from the power source 4 to theload 3 in the lowest phase, based on variables acquired before executionof the lowest phase or before the increase in temperature of the load 3in the lowest phase. Thereby, since it is possible to omit theacquisition of variables for the phase where the rate of temperatureincrease is the lowest, it is possible to promptly execute the phasewhere the rate of temperature increase is the lowest. Also, it ispossible to simplify the control on the phase where the rate oftemperature increase is the lowest.

The multiple phases include the first phase, and the second phase wherethe temperature or average temperature of the load 3 is higher than inthe first phase, and the number of variables that are acquired by thecontrol unit 8 before execution of the first phase or before theincrease in temperature of the load 3 in the first phase and are used inthe control on the power that is supplied from the power source 4 to theload 3 in the first phase may be larger than the number of variablesthat are acquired by the control unit 8 before execution of the secondphase or before the increase in temperature of the load 3 in the secondphase and are used in the control on the power that is supplied from thepower source 4 to the load 3 in the second phase. Thereby, environmentsettings at the start of the phase increase in the phase where the rateof temperature increase is higher, so that it is possible to increasethe temperatures of the load 3 and the aerosol generation article 9 morestably and faster.

The multiple phases include a phase where the temperature or averagetemperature of the load 3 is highest, and the control unit 8 may notacquire variables that are used in the control on the power that issupplied from the power source 4 to the load 3 in the highest phasebefore execution of the highest phase or before the increase intemperature of the load 3 in the highest phase or may not execute thecontrol on the power that is supplied from the power source 4 to theload 3 in the highest phase, based on variables acquired beforeexecution of the highest phase or before the increase in temperature ofthe load 3 in the highest phase. Thereby, since it is possible to omitthe acquisition of variables for the phase where the temperature oraverage temperature is the highest, it is possible to promptly executethe phase where the temperature or average temperature is the highest.Also, it is possible to simplify the control on the phase where thetemperature or average temperature is the highest.

The rate of temperature increase of the load 3 in the second phase maybe lower than the rate of temperature increase of the load 3 in thefirst phase, and the number of times of changing variables and/oralgorithms that are used in the control on the second phase duringcontrol execution of the second phase may be larger than the number oftimes of changing variables and/or algorithms that are used in thecontrol on the first phase during control execution of the first phase.Thereby, the number of change times during the phase increases in thephase where the rate of temperature increase of the load 3 is lower, sothat the temperatures of the load 3 and the aerosol generation article 9can be further highly controlled to stably generate aerosols.

Herein, the change of variables that are used in the control includeschanging one variable to another variable and changing a value stored ina variable, for example.

The change of algorithm includes changing one algorithm to anotheralgorithm, changing a function, processing and a variable that are usedin an algorithm, changing a part of a function and changing a part ofprocessing, for example.

The control unit 8 may be configured not to change a variable and/or analgorithm that is used in the control on a phase of the multiple phaseswhere the rate of temperature increase of the load 3 is the highest,during control execution of the highest phase. Thereby, it is possibleto omit the acquisition of variables for the phase where the rate oftemperature increase is the highest, and to simplify the control on thephase where the rate of temperature increase is the highest.

The temperature or average temperature of the load 3 in the second phasemay be higher than the temperature or average temperature of the load 3in the first phase, and the number of times of changing variables and/oralgorithms that are used in the control on the second phase duringcontrol execution of the second phase may be larger than the number oftimes of changing variables and/or algorithms that are used in thecontrol on the first phase during control execution of the first phase.Thereby, the number of change times during the phase increases in thephase where the temperature or average temperature of the load 3 ishigher, so that the temperatures of the load 3 and the aerosolgeneration article 9 can be further highly controlled to stably generateaerosols.

The control unit 8 may be configured not to change a variable and/or analgorithm that is used in the control on a phase of the multiple phaseswhere the temperature or average temperature of the load 3 is thelowest, during control execution of the lowest phase. Thereby, since itis possible to omit the acquisition of variables for the phase where thetemperature or average temperature is the lowest, it is possible topromptly execute the phase where the temperature or average temperatureis the lowest. Also, it is possible to simplify the control on the phasewhere the temperature or average temperature is the lowest.

The rate of temperature increase of the load 3 in the second phase maybe lower than the rate of temperature increase of the load 3 in thefirst phase, the control unit 8 may be configured to detect inhalationof aerosols generated from the aerosol generation article 9, and theincrease width of the power that is supplied from the power source 4 tothe load 3 in accordance with the inhalation detected in the secondphase may be set greater than the increase width of the power that issupplied from the power source 4 to the load 3 in accordance with theinhalation detected in the first phase. Thereby, the temperature can berecovered with a larger increase width with respect to the decrease intemperature due to the inhalation in the phase where the rate oftemperature increase of the load 3 is lower, so that it is possible tosuppress the amount of aerosol generation and the temperature of theload 3 from being lowered due to the inhalation.

The temperature or average temperature of the load 3 in the second phasemay be higher than the temperature or average temperature of the load 3in the first phase, the control unit 8 may be configured to detectinhalation of aerosols generated from the aerosol generation article 9,and the increase width of the power that is supplied from the powersource 4 to the load 3 in accordance with the inhalation detected in thesecond phase may be set greater than the increase width of the powerthat is supplied from the power source 4 to the load 3 in accordancewith the inhalation detected in the first phase. Thereby, thetemperature can be recovered with a larger increase width with respectto the decrease in temperature due to the inhalation in the phase wherethe temperature or average temperature of the load 3 is higher, so thatit is possible to suppress the amount of aerosol generation and thetemperature of the load 3 from being lowered due to the inhalation.

The control unit 8 may be configured to obtain degrees of progress,based on different variables, for each of the multiple phases. In thisway, a variable corresponding to the degree of progress is changed foreach phase, so that it is possible to recognize the progress of phasemore appropriately.

The control unit 8 may be configured to obtain a degree of progress of aphase of the multiple phases where the rate of temperature increase ofthe load 3 is the highest, based on time. In this way, it is possible tosuppress the load 3 from being overheated by determining temporally thedegree of progress of the phase where the rate of temperature increaseis high.

The control unit 8 may be configured to obtain a degree of progress of aphase of the multiple phases where the temperature or averagetemperature of the load 3 is the lowest, based on time. In this way, itis possible to suppress the load 3 from being overheated by determiningtemporally the degree of progress of the phase where the temperature oraverage temperature of the load 3 is the lowest.

The control unit 8 may be configured to detect inhalation of aerosolsgenerated from the aerosol generation article 9, and to obtain a degreeof progress of a phase of the multiple phases where the rate oftemperature increase of the load 3 is the lowest, based on thetemperature of the load 3 or the inhalation. In this way, the degree ofprogress is determined based on the temperature of the load 3 or theinhalation, so that the degree of progress of the phase can bedetermined based on a result of the aerosol generation of the aerosolgeneration article 9. Therefore, it is possible to generate moreaerosols from the aerosol generation article 9.

The control unit 8 may be configured to detect inhalation of aerosolsgenerated from the aerosol generation article 9, and to obtain a degreeof progress of a phase of the multiple phases where the temperature oraverage temperature of the load 3 is the highest, based on thetemperature of the load 3 or the inhalation. In this way, the degree ofprogress is determined based on the temperature of the load 3 or theinhalation in the phase where the temperature or average temperature isthe highest, so that the degree of progress of the phase can bedetermined based on a result of the aerosol generation of the aerosolgeneration article 9. Therefore, it is possible to generate moreaerosols from the aerosol generation article 9.

The control unit 8 may be configured to execute the feedback control inthe multiple phases where the target temperatures are different, and toset at least one of the gain in the feedback control and the upper limitvalue of the power that is supplied from the power source 4 to the load3 different in each of the multiple phases. The control modes in themultiple phases relating to the heating are different, so that a controlmode having a characteristic suitable for a phase can be used and thetemperatures of the load 3 and the aerosol generation article 9, whichis heated by the load 3, can be further highly controlled. Therefore,even with the aerosol generation article 9 having a complicatedstructure, it is possible to highly control aerosols to be generated.

In the third embodiment, the use phase may be further divided intomultiple phases, and the multiple phases may include the first phase andthe second phase.

In this case, the target temperature of the first phase may be lowerthan the target temperature of the second phase, and at least one of thegain and the upper limit value that are used in the first phase by thecontrol unit 8 may be set greater than at least one of the gain and theupper limit value that are used in the second phase by the control unit8. Thereby, at least one of the gain and the upper limit value can beincreased in the phase where the target temperature is lower. Also, inthe first phase, the rate of temperature increase of the load 3 can behighly controlled according to the target temperature by the feedbackcontrol, instead of the feed-forward control.

A change width of the temperature of the load 3 in the first phase maybe larger than a change width of the temperature of the load 3 in thesecond phase, and at least one of the gain and the upper limit valuethat are used in the first phase by the control unit 8 may be setgreater than at least one of the gain and the upper limit value that areused in the second phase by the control unit 8. Thereby, at least one ofthe gain and the upper limit value can be increased in the phase wherethe change width of the temperature of the load 3 is larger. Also, inthe first phase, the rate of temperature increase of the load 3 can behighly controlled according to the target temperature by the feedbackcontrol, instead of the feed-forward control.

The target temperature of the second phase may be higher than the targettemperature of the first phase, and a change width of at least one ofthe gain and the upper limit value that are used in the first phase bythe control unit 8 may be set smaller than a change width of at leastone of the gain and the upper limit value that are used in the secondphase by the control unit 8. Thereby, the change width of at least oneof the gain and the upper limit value can be increased in the phasewhere the target temperature is higher. Also, in the first phase, therate of temperature increase of the load 3 can be highly controlledaccording to the target temperature by the feedback control, instead ofthe teed-forward control.

The change width of the temperature of the load 3 in the second phasemay be smaller than the change width of the temperature of the load 3 inthe first phase, and a change width of at least one of the gain and theupper limit value that are used in the first phase by the control unit 8may be set smaller than at least one of the gain and the upper limitvalue that are used in the second phase by the control unit 8. Thereby,the change width of at least one of the gain and the upper limit valuecan be increased in the phase where the change width of the temperatureof the load 3 is smaller. Also, in the first phase, the rate oftemperature increase of the load 3 can be highly controlled according tothe target temperature by the feedback control, instead of thefeed-forward control.

The control unit 8 may be configured to change at least one of thetarget temperature, the gain and the upper limit value of the power ofthe second phase, based on the degree of progress of the first phase.Thereby, it is possible to change a variable value of a later phase,based on a degree of progress of an earlier phase. Therefore, a smoothshift from the earlier phase to the later phase is possible.

The control unit 8 may be configured to execute the feedback control inthe multiple phases, and to set different gains in the feedback controlin each of the multiple phases. Thereby, it is possible to performappropriate control in each phase by the feedback control.

The diverse controls by the control unit 8 may also be implemented asthe control unit 8 executes a program.

FIG. 29 is a table showing comparison of the preparation phase and theuse phase that are executed by the control unit in accordance with thethird embodiment. As described above, the preparation phase is a phasecorresponding to the preparation state where the load 3 cannot generatethe predetermined amount or more of aerosols from the aerosol generationarticle 9, for example. Also, the use phase is a phase corresponding tothe use state where the load 3 can generate the predetermined amount ormore of aerosols from the aerosol generation article 9, for example.Therefore, in order to generate aerosols from the aerosol generationarticle 9, it is necessary for the control unit 8 to shift a phase to beexecuted in order from the preparation phase to the use phase.

As described in the first embodiment, the control mode that is used inthe preparation phase is the feed-forward control. The end condition ofthe preparation phase is that a predetermined time elapses since thestart of the preparation phase, for example.

In the preparation phase, the load 3 in the preparation state is shiftedto the use state, and aerosols are quickly generated from the aerosolgeneration article 9. Therefore, the execution time of the preparationphase is shorter than the execution time of the use phase.

The preparation phase is provided so as to shift the load 3 in thepreparation state to the use state. In the preparation phase, theaerosol generation is not required, and the power consumption per unittime in the preparation phase is larger than the power consumption perunit time in the use phase. In the meantime, since the preparation phaseis preferably executed only for a short time, a total amount of powerconsumption over the entire preparation phase is smaller than a totalamount of power consumption over the entire use phase.

In the feed-forward control that is used in the preparation phase, it isdifficult to reflect a state of the control target in the control duringexecution of the control. Therefore, in the preparation phase, asdescribed above, an environment setting of changing the controlcharacteristic may be performed based on the measured temperature valueat the start of the preparation phase, the charging rate of the powersource 4, or the like. By the environment setting, the state of the load3 and/or the aerosol generation article 9 at the end of the preparationphase can be made uniform.

In the preparation phase, the control variable (control parameter) orcontrol function may be changed or may not be changed from apredetermined value or function before execution of the phase.

The preparation phase is provided so as to shift the load 3 in thepreparation state to the use state. In the preparation phase, theaerosol generation is not required, and the inhalation by the user ofthe aerosol generation device 1 is not assumed in the preparation phase.Therefore, in the preparation phase, the recovery of the decrease intemperature due to the user's inhalation is not performed.

The preparation phase is preferably executed only for a short time forthe purpose thereof. Therefore, as the input parameter of thefeed-forward control that is executed in the preparation phase, thetimer value t, i.e., the operating time is used. The operating time thatincreases securely over time is used as the input parameter, so that thepreparation phase can be securely progressed to shorten the operatingtime as much as possible.

The change in the measured temperature value (temperature profile) inthe preparation phase shows a more linear increase trend because itshifts the load 3 from the preparation state to the standby state in atime as short as possible.

In contrast, as described in the second embodiment, the control modethat is used in the use phase is the feedback control, and thefeed-forward control may also be used partially.

Since one of purposes of the use phase is to generate more aerosols fromthe aerosol generation article 9, it is necessary to design morecarefully the condition as to whether to end the use phase. Therefore,as the end condition of the use phase, for example, lapse of apredetermined time, reaching a predetermined temperature or lapse of apredetermined time and reaching a predetermined temperature are used.

The use phase is used so as to generate more aerosols from the aerosolgeneration article 9. Therefore, an execution time period of the usephase is longer than an execution time period of the preparation phase.

The load 3 is already in the use state upon execution of the use phase.Therefore, since it is not necessary to considerably increase thetemperature of the load 3 in the use phase, as compared to thepreparation phase, an amount of power that is used in the use phase issmaller than an amount of power that is used in the preparation phaseand the power consumption in the use phase is less than the powerconsumption in the preparation phase. In the meantime, since it isnecessary to generate many aerosols from the aerosol generation article9 in the use phase, the total amount of power over the entire use phaseis larger than the total amount of power in the preparation phase. Sincethe feedback control is mainly executed in the use phase, theenvironment setting at the start of the use phase may not be required orthe measured temperature value at the end of the preparation phase maybe used as the environment temperature.

In the use phase, for example, the control variable such as a gain maybe changed to highly control the temperature of the load 3 and/or thetemperature of the aerosol generation article 9.

In the use phase, since it is necessary to stabilize aerosols that aregenerated from the aerosol generation article 9, the recovery of thedecrease in temperature due to the inhalation is executed.

When executing the feed-forward control in the use phase, the inputparameter of the feed-forward control in the use phase may be any one ofthe timer value t, the measured temperature value and the puff profileor a combination thereof, for example. Since it is necessary to generatemore aerosols from the aerosol generation article 9 in the use phase, itis necessary to further highly control the temperatures of the load 3and the aerosol generation article 9. Therefore, it should be noted thatthe measured temperature value or the puff profile, which increases onlywhen the phase progresses, can be used as the input parameter of thefeed-forward control.

Since the temperature of the load 3 is controlled in the use phase sothat the aerosol generation position of the aerosol generation article 9changes over time, the temperature of the load 3 changes in a curve inthe use phase.

In the third embodiment as described above, the feed-forward control isexecuted in the preparation phase and the feedback control is executedin the use phase, so that aerosols are generated. Therefore, forexample, as compared to a case where only the feedback control is used,it is possible to improve the convenience for the user who inhalesaerosols, to improve the power efficiency, and to stably generateaerosols.

Fourth Embodiment

In a fourth embodiment, a case where the power that is supplied to theload 3 is controlled using a larger value of an operation value obtainedas a result of the feedback control in the use phase and a predeterminedvalue is described. By the control, it is possible to suppress thedecrease in temperature of the load 3 that occurs upon shift from thepreparation phase to the use phase, for example.

The control unit 8 in accordance with the fourth embodiment isconfigured to determine the power that is supplied from the power source4 to the load 3, based on comparison between an operation value obtainedin the feedback control and a predetermined value, for example. Forexample, the predetermined value may be a minimum guaranteed value.Thereby, as compared to a case where there is no minimum guaranteedvalue, it is possible to suppress the temperatures of the load 3 and theaerosol generation article 9 from dropping sharply.

The control unit 8 may also be configured to determine the power that issupplied from the power source 4 to the load 3, based on a larger valueof the operation value and the predetermined value. Thereby, it ispossible to prevent a situation where the power that is supplied to theload 3 is controlled based on a value smaller than the predeterminedvalue and thus the temperatures of the load 3 and the aerosol generationarticle 9 drop sharply.

The control unit 8 may be configured to control the power that issupplied from the power source 4 to the load 3 in the multiple phases,the multiple phases may include the first phase, and the second phasethat is executed after the first phase, and the predetermined value thatis used in the second phase may be determined based on the power that issupplied from the power source 4 to the load 3 in the first phase. Inthis way, the predetermined value that is used in the second phase isdetermined based on the power used in the first phase, so that it ispossible to suppress the decrease in temperatures of the load 3 and theaerosol generation article 9 upon shift from the first phase to thesecond phase.

The predetermined value that is used in the second phase may also bedetermined based on a value relating to power that is finally determinedin the first phase. In this way, the predetermined value that is used inthe second phase is determined based on a value relating to power thatis finally determined in the first phase, so that it is possible toefficiently suppress the decrease in temperatures of the load 3 and theaerosol generation article 9 upon shift from the first phase to thesecond phase.

The control unit 8 may be configured to execute the feedback control sothat the temperature of the load 3 gradually increases, and thepredetermined value may change with the increase in temperature of theload 3. In this case, since the minimum guaranteed value is changed asthe phase progresses, it is possible to use the appropriate minimumguaranteed value corresponding to the phase progress. Therefore, evenwhen the phase progresses, it is possible to suppress the temperature ofthe load 3 from dropping sharply.

The control unit 8 may also be configured to execute the feedbackcontrol so that the operation value gradually increases, and thepredetermined value may change with the increase in temperature of theload 3. Thereby, even when the phase progresses and the temperature ofthe load 3 increases, it is possible to suppress the temperature of theload 3 from dropping sharply by using the appropriate minimum guaranteedvalue corresponding to the phase progress.

The control unit 8 may also be configured to gradually increase a gainin the feedback control. Thereby, it is possible to increase theoperation value as the phase progresses. Therefore, since it is possibleto increase the temperature of the load 3 and/or the aerosol generationarticle 9 according to the progress of the phase, it is possible tostably generate aerosols from the aerosol generation article 9 over theentire use phase, as described in the second embodiment.

The control unit 8 may also be configured to gradually increase theupper limit of the power that is supplied from the power source 4 to theload 3 in the feedback control. Thereby, it is possible to increase theoperation value as the phase progresses. Therefore, since it is possibleto increase the temperature of the load 3 and/or the aerosol generationarticle 9 according to the progress of the phase, it is possible tostably generate aerosols from the aerosol generation article 9 over theentire use phase, as described in the second embodiment.

The predetermined value may gradually decrease. In this case, it ispossible to reduce the minimum guaranteed value with the phase progress.In particular, when the minimum guaranteed value is provided so as tosuppress the decrease in temperature of the load 3 that occurs uponshift from the preparation phase to the use phase, the necessity toprovide the minimum guaranteed value decreases with the phase progress.Therefore, it is possible to reduce an influence of the minimumguaranteed value on the control with the phase progress.

The control unit 8 may be configured to change the predetermined valueto zero during the execution of the feedback control. In this case, itis possible to suppress an influence of the minimum guaranteed value onthe control, which is not required as the phase progresses, as describedabove.

Herein, the change of the predetermined value to zero includestemporarily changing the predetermined value to zero.

The control unit 8 may decrease the predetermined value when anovershoot where the temperature of the load 3 changes by a thresholdvalue or larger per predetermined time is detected. In this way, whenthe overshoot of the temperature of the load 3 is detected, the minimumguaranteed value is decreased to reduce an influence of the minimumguaranteed value on the operation value obtained by the feedback controlthat is executed by the control unit 8. Therefore, it is possible toearly resolve the overshoot.

When the overshoot is resolved, he control unit 8 may return thepredetermined value to a value before the overshoot is detected.Thereby, it is possible to return the minimum guaranteed value, based onthe resolving of the overshoot, and to suppress the temperatures of theload 3 and the aerosol generation article 9 from dropping sharply afterthe overshoot is resolved.

The predetermined value may be determined as a value or larger necessaryto keep the temperature of the load 3. Thereby, the minimum guaranteedvalue is determined so that the temperature of the load 3 is notdecreased, so that it is possible to suppress the decrease intemperatures of the load 3 and the aerosol generation article 9.

The control unit 8 may also be configured to determine or correct thepredetermined value, based on the temperature of the load 3. Thereby,since the minimum guaranteed value is determined or corrected based onthe temperature of the load 3, the minimum guaranteed value becomes avalue that reflects a state of the load 3, as compared to a case wherethe minimum guaranteed value is not determined or corrected. Therefore,it is possible to suppress the decrease in temperature of the load 3.

The control unit 8 may also be configured to determine or correct thepredetermined value so that an absolute value of a difference betweenthe temperature of the load 3 and the predetermined temperature does notincrease. Thereby, since the minimum guaranteed value is determined orcorrected so that the difference between the predetermined temperatureand the temperature of the load 3 does not increase, the minimumguaranteed value becomes a value that reflects the progress of the usephase, as compared to a case where the minimum guaranteed value is notdetermined or corrected. Therefore, it is possible to suppress thedecrease in temperature of the load 3.

The control unit 8 may also be configured to acquire the temperature ofthe load 3, to control the power that is supplied from the power source4 to the load 3 by the feedback control, based on the difference betweenthe temperature of the load 3 and the predetermined temperature, and tocorrect the operation value obtained in the feedback control so as tosuppress the decrease in temperature of the load 3. Thereby, theoperation value is corrected to a value that reflects the temperature ofthe load 3, which is a control value of the feedback control that isexecuted by the control unit 8. Therefore, even when a small operationvalue is obtained in the feedback control, it is possible to effectivelysuppress the temperature of the load 3 from dropping sharply.

The diverse controls by the control unit may also be implemented as thecontrol unit 8 executes a program.

Example 4A

FIG. 30 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 4A.

The comparison unit 15 provided in the control unit 8 in accordance withExample 4A compares an operation value obtained as a result of thefeedback control and a predetermined value, and outputs a larger value,in the use phase.

The predetermined value is, for example, a minimum guaranteed value ofthe duty command value indicative of the duty ratio relating to thepower that is supplied to the load 3. As the predetermined value, forexample, the duty ratio at the end of the preparation phase may be usedas the value relating to the power in the preparation phase.

The comparison unit 15 is more specifically described. The comparisonunit 15 is input with a duty operation value from the limiter unit 14and a minimum guaranteed value, in the use phase. The comparison unit 15compares the duty operation value and the minimum guaranteed value, andobtains a larger value as the duty command value. The control unit 8controls the power that is supplied to the load 3, based on the dutycommand value. In the meantime, the duty command value may be applied tothe switch 25 provided between the power source 4 and the load 3 or maybe applied to the DC/DC converter provided between the power source 4and the load 3.

FIG. 31 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 4A.

The processing from step S3101 to step S3106 is the same as theprocessing from step S1901 to step S1906 in FIG. 19 .

In step S3107, the comparison unit 15 of the control unit 8 determineswhether the duty ratio D_(cmdd) indicated by the duty operation valueinput from the limiter unit 14 is equal to or larger than the minimumguaranteed value.

When it is determined that the duty ratio D_(cmdd) is equal to or largerthan the minimum guaranteed value (a determination result in step S3107is affirmative), the control unit 8 controls the power that is suppliedto the load 3, based on the duty command value indicative of the dutyratio D_(cmdd), in step S3108, and then the processing returns to stepS3101.

When it is determined that the duty ratio D_(cmdd) is not equal to orlarger than the minimum guaranteed value (a determination result in stepS3107 is negative), the control unit 8 controls the power that issupplied to the load 3, based on the minimum guaranteed value, in stepS3109, and then the processing returns to step S3101.

The operational effects of Example 4A described above are described.

For example, in order to prevent the user from feeling uncomfortable,the aerosol generation device 1 configured to heat the aerosolgeneration article 9 for aerosol generation controls the power that issupplied to the load 3 so that aerosols generated by the heating do notlargely vary. As described above, the control on the power that issupplied to the load 3 is preferably executed in the multiple phasessuch as the preparation phase and the use phase, for example. As anexample, as described in the first embodiment and the second embodiment,the control unit 8 executes the use phase after the preparation phase,so that it is possible to achieve both the early aerosol generation bythe aerosol generation device 1 and the stable aerosol generationthereafter.

Also, in the control for shift from one phase to another phase, it ispreferably to suppress the temperature of the load 3 from changingsharply upon the phase shift. In particular, when the controls usedbefore and after the shift are more different, the shift time from onephase to another phase becomes a transition period of the control.Therefore, it can be said that the temperature of the load 3, which is acommon control amount, is likely to vary through the multiple phases.

In Example 4A, upon the phase shift, the control parameter used in thephase before the shift is used as the minimum guaranteed value.Therefore, as compared to a case where the minimum guaranteed value isnot used, it is possible to suppress the temperatures of the load 3 andthe aerosol generation article 9 from changing sharply upon the phaseshift.

Example 4B

In Example 4B, control of appropriately suppressing overshoot even whenthe overshoot, i.e., the sharp increase occurs in the temperature of theload 3 is described.

FIG. 32 is a graph depicting an example of a generation state ofovershoot in the temperature of the load 3. In FIG. 32 , it is assumedthat the minimum guaranteed value is constant.

The temperature of the load 3 gradually increases as the timer value t,which is an example of an index indicative of a degree of progress of aphase in the use phase, increases, i.e., over time.

The limiter width increases stepwise as the timer value t increases.

The gain unit 12 obtains a duty ratio, based on a difference between themeasured temperature value and the use phase end temperature.

The limiter unit 14 obtains a duty ratio within a range of the limiterwidth, based on the duty ratio obtained by the gain unit 12, and obtainsa duty operation value indicative of the duty ratio within the range ofthe limiter width. Since the limiter width increases stepwise, the dutyratio indicated by the duty operation value may also increase stepwise.

When overshoot occurs in the temperature of the load 3 in the use phase,the control unit 8 decreases the duty command value so as to suppressthe overshoot. For example, when the temperature of the load 3 exceedsinstantly the use phase end temperature in the feedback control, thecontrol unit 8 lowers the temperature of the load 3 that is a controlvalue by decreasing the duty ratio that is an operation value. However,since the duty ratio indicated by the duty command value does not fallbelow the minimum guaranteed value, there is a possibility that thetemperature of the load 3 will be insufficiently recovered.

Therefore, in Example 4B, the minimum guaranteed value is graduallydecreased according to the degree of progress of the use phase, based onthe input parameter including at least one of the timer value t, thetemperature of the load 3 and the puff profile, so that the temperatureof the load 3 can be appropriately recovered even when the overshootoccurs in the temperature of the load 3. The minimum guaranteed value isprovided so as to suppress the sharp change in temperatures of the load3 and the aerosol generation article 9 which may be generated upon shiftfrom the preparation phase to the use phase. That is, when the controlunit 8 executes once the use phase, the necessity to provide the minimumguaranteed value is reduced. Therefore, even when the minimum guaranteedvalue is gradually decreased according to the degree of progress of theuse phase, the control unit 8 can control highly the temperatures of theload 3 and the aerosol generation article 9.

FIG. 33 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 4B.

A gradual decrease unit 18 provided in the control unit 8 in accordancewith Example 4B decreases gradually the minimum guaranteed valueindicative of the duty ratio at the end of the preparation phase, basedon the degree of progress of the use phase indicated by the inputparameter including at least one of the timer value t, the measuredtemperature value and the puff profile, for example. In the meantime,ones of the timer value t, the measured temperature value and the puffprofile that are used when the gradual decrease unit 18 indicates thedegree of progress of the use phase may be the same as or different fromones that are used when the limiter change unit 13 and/or the gainchange unit 17 indicates the degree of progress of the use phase.

The comparison unit 15 compares the duty ratio D_(cmdd)limiter-processed by the limiter unit 14 and the minimum guaranteedvalue decreased gradually by the gradual decrease unit 18, and obtainsone indicative of a larger value as a result of the comparison, as theduty command value.

FIG. 34 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 49.

The processing from step S3401 to step S3406 is the same as theprocessing from step S1901 to step S1906 in FIG. 19 .

In step S3407, the control unit 8 acquires the input parameter.

In step S3408, the gradual decrease unit 18 of the control unit 8obtains the minimum guaranteed value decreased gradually, based on theinput parameter, for example. For example, when the input parameter isthe timer value t, it is determined that the larger the timer value tis, the further the use phase progresses, and the minimum guaranteedvalue is reduced. In the meantime, the gradual decrease unit 18 maydecrease gradually the minimum guaranteed value, based on at least oneof the measured temperature value and the puff profile, instead of thetimer value t or together with the timer value t.

In step S3409, the comparison unit 15 of the control unit 8 determineswhether the limiter-processed duty ratio D_(cmdd) is equal to or largerthan the minimum guaranteed value decreased gradually.

When it is determined that the duty ratio D_(cmdd) is equal to or largerthan the minimum guaranteed value decreased gradually (a determinationresult in step S3409 is affirmative), the control unit 8 controls thepower that is supplied to the load 3, based on the duty command valueindicative of the duty ratio D_(cmdd), in step S3410, and then theprocessing returns to step S3401.

When it is determined that the duty ratio D_(cmdd) is not equal to orlarger than the minimum guaranteed value decreased gradually (adetermination result in step S3409 is negative), the control unit 8controls the power that is supplied to the load 3, based on the minimumguaranteed value decreased gradually, in step S3411, and then theprocessing returns to step S3401.

In Example 4B as described above, the degree of progress of the usephase is determined based on the input parameter including at least oneof the timer value t, the temperature of the load 3 and the puffprofile, and the minimum guaranteed value is gradually decreased as thedegree of progress of the use phase progresses. Thereby, when theovershoot occurs in the load 3, it is possible to sufficiently suppressthe power that is supplied to the load 3, so that it is possible toresolve the overshoot promptly and appropriately.

Example 4C

Example 4C is a modified example of Example 4B. In Example 4C, when theuse phase progresses, the control is performed so that the dutyoperation value is used as the duty command value. In other words, inthe control of Example 4C, the minimum guaranteed value is invalidatedor is made to zero, based on the input parameter or the processing ofthe comparison unit 15 based on the minimum guaranteed value iscancelled.

FIG. 35 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 4C.

A change unit 19 provided in the control unit 8 in accordance withExample 4C switches the minimum guaranteed value to zero or invalidatesthe same when the input parameter including at least one of the timervalue t, the measured temperature value and the puff profile indicates apredetermined degree of progress, for example.

When the minimum guaranteed value is switched to zero by the change unit19, the comparison unit 15 sets the duty operation value input from thelimiter unit 14, as the duty command value.

The control unit 8 controls the power that is supplied to the load 3,based on the duty command value corresponding to the duty operationvalue.

FIG. 36 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 4C. in FIG. 36 ,a case where the degree of progress of the use phase is determined usingthe timer value t as the input parameter is exemplified. However, thedegree of progress of the use phase may also be determined using themeasured temperature value or the puff profile.

The processing from step S3601 to step S3606 is the same as theprocessing from step S1901 to step S1906 in FIG. 19 .

In step S3607, the change unit 19 of the control unit 8 determineswhether the timer value t is less than a predetermined time t_(thre2),for example.

When it is determined that the timer value t is less than apredetermined time t_(thre2) (a determination result in step S3607 isaffirmative), the comparison unit 15 of the control unit 8 determineswhether the limiter-processed duty ratio D_(cmdd) is equal to or largerthan the minimum guaranteed value, in step S3608.

When it is determined by the Change unit 19 that the tinier value t isnot less than the predetermined rime t_(thre2) (a determination resultin step S3607 is negative), or when it is determined by the comparisonunit 15 that the duty ratio D_(cmdd) is equal to or larger than theminimum guaranteed value (a determination result in step S3608 isaffirmative), the control unit 8 controls the power that is supplied tothe load 3, based on the duty command value indicative of the duty ratioD_(cmdd), in step S3609, and then the processing returns to step S3601.

When it is determined by the comparison unit 15 that the duty ratioD_(cmdd) is not equal to or larger than the minimum guaranteed value (adetermination result in step S3608 is negative), the control unit 8controls the power that is supplied to the load 3, based on the minimumguaranteed value, in step S3610, and then the processing returns to stepS3601.

In Example 4C as described above, it is determined whether the progressof the use phase is equal to or greater than the predetermined value,based on the input parameter, and when it is determined that theprogress of the use phase is equal to or greater than the predeterminedvalue, the control is switched to the control in which the minimumguaranteed value is not used. Thereby, when a disturbance occurs in thebehavior of the temperature of the load 3, such as the overshoot in thetemperature, the feedback control functions to output a large operatingamount, so that it is possible to highly control the power that issupplied to the load 3. Therefore, it is possible to resolve or convergepromptly and appropriately the disturbance in the behavior of thetemperature of the load 3.

Example 4D

Example 4D is a modified example of Example 4C. In Example 4D, when eovershoot of the temperature is detected, the control unit 8 invalidatesthe minimum guaranteed value, sets the minimum guaranteed value to zeroor cancels the processing of the comparison unit 15 based on the minimumguaranteed value.

FIG. 37 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 4D.

An overshoot detection unit 20 provided in the control unit inaccordance with Example 4D invalidates or reduces the minimum guaranteedvalue when the overshoot of the temperature is detected, for example,and validates or increases again the minimum guaranteed value when theovershoot of the temperature is resolved.

FIG. 38 is a flowchart depicting an example of processing in theovershoot detection unit 20 in accordance with Example 4D.

In step S3801, the overshoot detection unit 20 executes detection of theovershoot of the temperature, and determines whether the overshoot isdetected.

When it is determined that the overshoot is not detected (adetermination result in step S3801 is negative), the processing of stepS3801 is repeated.

When it is determined that the overshoot is detected (a determinationresult in step S3801 is affirmative), the overshoot detection unit 20invalidates or reduces the minimum guaranteed value, in step S3802.

In step S3803, the overshoot detection unit 20 determines whether theovershoot has been resolved.

When it is determined that the overshoot has not been resolved (adetermination result in step S3803 is negative), the processing of stepS3803 is repeated.

When is determined that the overshoot has been resolved, the overshootdetection unit 20 returns the minimum guaranteed value, in step S3804.

In Example 4D as described above, when the overshoot of the temperatureis detected, the minimum guaranteed value is invalidated or reduced, sothat it is possible to resolve promptly and appropriately the overshootof the temperature.

Example 4E

In Example 4E, the control unit 8 obtains a minimum guaranteed valuehaving a duty ratio necessary to keep the temperature of the load 3,based on the input parameter indicative of the degree of progress in theuse phase, sets, as the duty command value, a larger value of the dutyoperation value obtained by the gain unit 12 and the minimum guaranteedvalue, and controls the power that is supplied to the load 3, based onthe duty command value.

In Example 4E, a case where the measured temperature value is used asthe input parameter indicative of the degree of progress in the usephase is described as an example. However, the timer value t or the puffprofile may also be used as the input parameter.

FIG. 39 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 4E.

A heat-retention control unit 21 provided in the control unit 8 inaccordance with Example 4E obtains a minimum guaranteed value that is aduty ratio necessary to keep the temperature of the load 3, based on themeasured temperature value, for example, and outputs the minimumguaranteed value necessary for heat retention to the comparison unit 15.For example, the measured temperature value and the minimum guaranteedvalue that is a duty ratio necessary for heat retention of the load 3corresponding to the measured temperature value are analytically orexperimentally. Then, the heat-retention control unit 21 may also use amodel formula or a table relating to a correlation between the measuredtemperature value and the minimum guaranteed value derived from theanalysis result or experiment result, for example. In the meantime, theheat-retention control unit 21 may also use a correlation betweenanother input parameter such as the timer value t or the puff profileindicative of the degree of progress in the use phase and the minimumguaranteed value.

In this way, the duty ratio necessary to keep the temperature of theload 3 is used as the minimum guaranteed value, so that the secondsub-phase included in the preparation phase can be incorporated into theuse phase. Thereby, the second sub-phase can be omitted from thepreparation phase. Therefore, in Example 4E, the time period of thepreparation phase can be shortened, and the decrease in temperature ofthe load 3 can be suppressed because the temperature of the load 3 iskept according to the minimum guaranteed value.

FIG. 40 is a flowchart depicting an example of processing in thepreparation phase by the control unit 8 in accordance with Example 4E.

The processing from step S4001 to step S4005 in FIG. 40 is the same asthe processing from step S501 to step S505 in FIG. 5 .

In the processing of FIG. 40 , it should be noted that the processing ofstep S4006 and step S4007 corresponding to step S506 and step S507 isomitted from the processing of FIG. 5 .

FIG. 41 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 4E.

In step S4101, the heat-retention control unit 21 of the control unit 8inputs the measured temperature value T_(HTR) from the temperaturemeasurement unit 6.

In step S4102, the heat-retention control unit 21 obtains the duty rationecessary to keep the temperature indicated by the measured temperaturevalue T_(HTR), and outputs a minimum guaranteed value D_(lim) (T_(HTR))indicative of the duty ratio necessary for heat retention to thecomparison unit 15. As an example, when the heat-retention control unit21 has the correlation between the input parameter and the minimumguaranteed value, as a model formula, D_(lim) (T_(HTR)) is a function.As an example, when the heat-retention control unit 21 has thecorrelation between the input parameter and the minimum guaranteedvalue, as a table, D_(lim) (T_(HTR)) is a query for the table.

The processing from step S4103 to step S4111 is the same as theprocessing from step S3101 to step S3109 in FIG. 31 . In the meantime,after step 4110 and step S4111, the processing may return to step S4103or step S4101.

In Example 4E as described above, it is possible to resolveappropriately the change in temperature such as overshoot while securingthe heat retention of the load 3. Also, in Example 4E, it is possible toomit the second sub-phase from the preparation phase, thereby shorteningthe preparation phase.

Fifth Embodiment

In an electronic cigarette or a heating type cigarette, in order not toimpair the amount and flavor and taste of aerosols generated from theaerosol generation article 9 even when the temperature of the load 3 isfeedback-controlled and the temperature of the load 3 is decreased dueto the user's inhalation, it is preferably to promptly recover thedecrease in temperature and to compensate for the temperature of theload 3.

However, for example, when the operating amount obtained by the feedbackcontrol is small, the sufficient power is not supplied to the load 3whose temperature has been decreased, so that it may take to recover thedecrease in temperature of the load 3.

Therefore, in a fifth embodiment, when the user's inhalation isdetected, the operating amount obtained by the feedback control istemporarily increased to promptly recover the decrease in temperature ofthe load 3 due to the inhalation. More specifically, when the decreasein temperature occurs due to the aerosol inhalation in the use phase,for example, the control unit 8 of the fifth embodiment performs controlof expanding the limiter width of the limiter unit 14 used in thefeedback control, as compared to the limiter width before the decreasein temperature occurs. Thereby, in the fifth embodiment, the decrease intemperature of the load 3 upon the inhalation is promptly recovered tocompensate for the temperature of the load 3. Therefore, even when theuser's inhalation is performed, it is possible to suppress the impair inamount and flavor and taste of aerosols generated from the aerosolgeneration article 9.

When the temperature drop of the load 3 is detected during the executionof the feedback control, the control unit 8 of the fifth embodiment maychange the value of the variable that is used in the feedback control soas to increase the power that is supplied from the power source 4 to theload 3. Thereby, as compared to a case where the value of the variablethat is used in the feedback control is not changed, it is possible topromptly recover the temperature of the load 3. Herein, the change ofthe variable that is used in the control includes changing one variableto another variable and changing a value stored in a variable, forexample.

When the drop is detected, the control unit 8 may increase at least oneof the gain that is used in the feedback control and the upper limitvalue of the power that is supplied from the power source 4 to the load3. Thereby, as compared to a case where both the gain and the upperlimit value of the power are not increased, the temperature of the load3 can be promptly recovered.

When the drop is detected, the control unit 8 may increase the targettemperature that is used in the feedback control. Thereby, as comparedto a case where the target temperature is not increased, the temperatureof the load 3 can be promptly recovered.

The control unit 8 may be configured to execute the feedback control sothat the temperature of the load 3 gradually increases, and may changethe variable to a value that is different from a value before thechange, based on the detection of the drop, when the drop is resolved.Thereby, for example, it is possible to supply more power to the load 3than before the drop is detected. As described in the second embodiment,in order to stabilize the amount of aerosols generated from the aerosolgeneration article 9, it is necessary to increase the temperature of theload 3 and the temperature of the aerosol generation article 9 heated bythe load 3 over time. Therefore, more power than before the drop isdetected is supplied to the load 3, so that it is possible to suppressthe decrease in the amount of aerosol generation before and after thedrop.

The control unit 8 may be configured to execute the feedback control sothat the power that is supplied from the power source 4 to the load 3gradually increases, and may change the variable to a value that isdifferent from a value before the change, based on the detection of thedrop, when the drop is resolved. Thereby, for example, it is possible tosupply more power to the load 3 than before the drop is detected. Asdescribed above, more power than before the drop is detected is suppliedto the load 3, so that it is possible to suppress the decrease in theamount of aerosol generation before and after the drop.

The control unit 8 may be configured to gradually increase at least oneof the gain that is used in the feedback control and the upper limitvalue of the power that is supplied from the power source 4 to the load3 as the feedback control progresses, may increase at least one of thegain and the upper limit value by an increment or larger correspondingto the progress of the feedback control when the drop is detected, andmay change at least one of the gain and the upper limit value to a valuethat is different from a value before the increase based on thedetection of the drop, when the drop is resolved. Thereby, for example,it is possible to supply more power to the load 3 than before the dropis detected. Therefore, it is possible to suppress the decrease in theamount of aerosol generation before and after the drop.

The control unit 8 may change at least one of the gain and the upperlimit value so as not to decrease when the drop is detected or when thedrop is resolved. Thereby, it is possible to suppress the temperature ofthe load 3 from being stagnant. Therefore, the amount of aerosolgeneration is difficult to decrease over time.

The control unit 8 may change at least one of the gain and the upperlimit value so as to increase when the drop is detected or when the dropis resolved. Thereby, it is possible to suppress the reduction in theamount of aerosol generation.

The control unit 8 may increase at least one of the gain and the upperlimit value by an increment corresponding to the progress of thefeedback control when the drop is resolved. Thereby, since it ispossible to increase the temperature of the load 3 in accordance withthe same control before the drop is detected, after the drop isresolved, it is possible to stably generate aerosols without beinginfluenced by the inhalation state. Therefore, the user of the aerosolgeneration device 1 does not feel uncomfortable with respect to theamount and flavor and taste of aerosols generated from the aerosolgeneration article 9 over the entire use phase. Therefore, it ispossible to improve the quality of the aerosol generation device 1.

When the drop is resolved, the control unit 8 may change at least one ofthe gain and the upper limit value to a value that is different from avalue before the increase based on the detection of the drop so that thehigher power than before the drop is detected is supplied from the powersource 4 to the load 3. Thereby, it is possible to suppress the amountof aerosol generation from being reduced.

The control unit 8 may be configured to reduce the amount in change ofthe variable with the progress of the feedback control. Thereby, thefeedback control functions to output a large operating amount with thephase progress, so that it is possible to suppress the change in avariable, whose degree of importance is lowered, from affecting thecontrol.

When the feedback control progresses by a predetermined degree ofprogress or greater and the drop is detected, the control unit 8 may setthe amount in change of the variable to zero. Thereby, even if the dropoccurs after the phase progresses to some extent, the variable may notbe changed. In the meantime, after the phase progresses to some extent,the drop is immediately resolved by the feedback control capable ofoutputting the large operating amount. Therefore, the amount of aerosolgeneration is suppressed from being reduced.

The control unit 8 may be configured to reduce an increase amount of atleast one of the gain and the upper limit value with the progress of thefeedback control. Thereby, the feedback control functions to output alarge operating amount with the phase progress, so that when a degree ofchange importance of at least one of the gain and the upper limit valueis lowered, it is possible to suppress the change of at least one of thegain and the upper limit value from affecting the control.

When the feedback control progresses by a predetermined degree ofprogress or greater and the drop is detected, the control unit 8 may setthe amount in change of at least one of the gain and the upper limitvalue to zero. Thereby, the feedback control normally functions tooutput a large operating amount with the phase progress, so that whenthe change of at least one of the gain and the upper limit value is notnecessary, the change of at least one of the gain and the upper limitvalue can be suppressed.

The control unit 8 may be configured to execute the feedback control sothat the temperature of the load 3 is constant, and may change thechanged variable to a value before the change, based on the detection ofthe drop, when the drop is resolved. Thereby, it is possible to promptlyresolve the drop and to return the control state to the state before thedrop is detected.

The control unit 8 may be configured to detect, as the drop, that thetemperature of the load 3 is decreased by a first threshold value orlarger or that the power that is supplied from the power source 4 to theload 3 is increased by a second threshold value or larger, the firstthreshold value may be a value by which it is possible to distinguish adecrease in temperature of the load 3 upon inhalation of aerosols fromthe aerosol generation article 9 and a decrease in temperature of theload 3 upon non-inhalation of aerosols, and the second threshold valuemay be a value by which it is possible to distinguish an increase inpower that is supplied from the power source 4 to the load 3 uponinhalation of aerosols from the aerosol generation article 9 and anincrease in power that is supplied from the power source 4 to the load 3upon non-inhalation of aerosols. Thereby, when the drop is caused due tothe inhalation of aerosols, it is possible to promptly suppress theamount of aerosol generation from being reduced.

When the temperature drop of the load 3 is detected during the executionof the feedback control, the control unit 8 may invalidate the upperlimit value of the power that is used in the feedback control andsupplied from the power source 4 to the load 3. Thereby, it is possibleto increase the power that is supplied to the load 3, based on the dropdetection, so that it is possible to promptly suppress the amount ofaerosol generation from being reduced due to the drop.

The diverse controls by the control unit 8 may also be implemented asthe control unit 8 executes a program.

Example 5A

FIG. 42 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 5A.

The limiter change unit 13 of the control unit 8 controls the increasewidth of the limiter width by the feed-forward control, based on theinput parameter.

When the user inhales aerosols, an air stream generated in the aerosolgeneration device 1 passes the vicinity of the load 3, so that thetemperature of the load 3 is temporarily decreased. When the aerosolinhalation is detected, the limiter change unit 13 of Example 5A expandstemporarily the increase width of the limiter width, thereby recoveringpromptly the decrease in temperature of the load 3 due to theinhalation.

FIG. 43 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 5A.

The processing from step S4301 to step S4303 is the same as theprocessing from step S1901 to step S1903 in FIG. 19 .

In step S4304, the control unit 8 determines whether the inhalation isdetected. The inhalation is detected based on an output value of asensor configured to detect a physical quantity that varies with theuser's inhalation, such as a flow rate sensor, a flow velocity sensorand a pressure sensor provided in the aerosol generation device 1, forexample.

When it is determined that the inhalation is not detected (adetermination result in step S4304 is negative), the processing proceedsto step S4306.

When it is determined that the inhalation is detected (a determinationresult in step S4304 is affirmative), the limiter change unit 13 changesa correlation for limiter width change so that the increase width of thelimiter width used in the limiter unit 14 is large with respect to aninput profile, in step S4305, and proceeds to step S4306.

The processing from step S4306 to step S4309 is the same as theprocessing from step S1904 to step S1907 in FIG. 19 .

In Example 5A as described above, when the inhalation is detected, theincrease width of the limiter width that is used in the limiter unit 14is expanded to increase the duty operation value that is obtained by thefeedback control, so that it is possible to promptly recover thedecrease in temperature of the load 3 due to the inhalation. Therefore,even when the user performs the inhalation, it is possible to suppressthe impair in the amount and flavor and taste of aerosols generated fromthe aerosol generation article 9.

Example 5B

In Example 5B, control of further increasing the increase width of thelimiter width when the inhalation is detected, as compared to theincrease width of the limiter width when the inhalation is not detected,is described.

FIG. 44 is a graph depicting an example of changes in the temperature ofthe load 3 and the limiter width. In FIG. 44 , the horizontal axisindicates the tinier value t, and the vertical axis indicates thetemperature or the limiter width.

The limiter change unit 13 of the control unit 8 controls the increasewidth of the limiter width so as to increase the temperature of the load3 after the inhalation is detected more than before the inhalation isdetected.

When the inhalation is not detected, the limiter change unit 13increases the limiter width as the timer value t increases, i.e., overtime, as shown with a line L_(50A).

When the inhalation is detected, the limiter change unit 13 changes thelimiter width so as to be larger than a change in the line L_(50A), asshown with a line L_(50B), after the temperature of the load 3 isrecovered.

In the meantime, as shown with a line L_(50C), the limiter change unit13 may change the limiter width after the end of the temperaturerecovery so as to be smaller than the limiter width while the decreasein temperature due to the inhalation is resolved. In this case, thelimiter change unit 13 may set the limiter width after the end of thetemperature recovery larger than the limiter width before the inhalationdetection. Also, the limiter change unit 13 may return the limiter widthafter the end of the temperature recovery to a state before theinhalation detection.

As an example, when the control unit 8 evaluates the degree of progressof the use phase by the temperature of the load 3, if the decrease intemperature occurs due to the inhalation, the degree of progress of theuse phase is stagnant. After the temperature of the load 3 is recovered,when the limiter width is changed as shown with the line L_(50A), thedegree of progress of the use phase is delayed, as compared to a casewhere the inhalation is not detected, because the line L_(50A) indicatesthe increase width when the inhalation is not detected. Therefore, whenthe inhalation is detected, the limiter change unit 13 changes thelimiter width so as to be larger than the change of the line L_(50A), asshown with the line L_(50B), after the temperature of the load 3 isrecovered. Thereby, it is possible to recover the delay in the degree ofprogress of the use phase due to the inhalation.

In the meantime, the limiter change unit 13 may change the limiter widthso as to be larger than the change when the inhalation is not detected,as shown with the line L_(50B), whenever the inhalation is detected.Thereby, even when the user of the aerosol generation device 1 performsthe inhalation in any puff profile, the degree of progress of the usephase can be made uniform. Therefore, the flavor and taste of aerosolsthat are generated from the aerosol generation article 9 can be madestable, irrespective of the puff profile, so that it is possible toimprove the quality of the aerosol generation device.

FIG. 45 depicts an example of the limiter change unit 13 in accordancewith Example 5B.

The limiter change unit 13 in accordance with Example 5B determines theincrease width of the limiter width, based on the input parameterincluding at least one of the timer value t, the measured temperaturevalue and the puff profile.

The limiter change unit 13 expands the limiter width when the inhalationis detected from the decrease in temperature of the load 3 or the puffprofile, for example. The larger the increase width of the limiter width(degree of expansion) is, it is possible to further promote thetemperature recovery of the load 3. That is, a degree of the temperaturerecovery of the load 3 is different between a case where the increasewidth of the limiter width shown in FIG. 45 is expanded to be small anda case where it is expanded to be large, in correspondence to an areaA₅₁ that is the difference. Therefore, the greater the degree ofdecrease in temperature of the load 3 is or the greater the necessity torecover the temperature of the load 3 is, an area defined by theincrease width of the limiter width shown with the upward sloping brokenline when the inhalation is not detected and the expanded increase widthshown with the dotted line is preferably larger.

FIG. 46 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 5B.

The processing from step S4601 to step S4603 is the same as theprocessing from step S4301 to step S4303 in FIG. 43 .

In step S4604, the limiter change unit 13 of the control unit 8determines whether a third relation of the input parameter and thelimiter width (hereinbelow, referred to as correlation for limiter widthchange) has been already changed, for example. Herein, the correlationfor limiter width change may also be expressed by correlation data orcorrelation function.

When it is determined that the correlation for limiter width change hasnot been already changed (a determination result in step S4604 isnegative), the processing proceeds to step S4607.

When it is determined that the correlation for limiter width change hasbeen already changed (a determination result in step S4604 isaffirmative), the limiter change unit 13 determines whether the decreasein temperature of the load 3 has been recovered, for example, whether apredetermined time has elapsed since the decrease in temperature of theload 3, in step S4605.

When it is determined that the decrease in temperature of the load 3 hasnot been recovered (a determination result in step S4605 is negative),the processing proceeds to step S4607.

When it is determined that the decrease in temperature of the load 3 hasbeen recovered (a determination result in step S4605 is affirmative),the limiter change unit 13 returns the correlation for limiter widthchange to an original state before the inhalation detection, in stepS4606, and the processing proceeds to step S4607.

The processing from step S4607 to step S4612 is the same as theprocessing from step S4304 to step S4309 in FIG. 43 .

In Example 5B as described above, when the inhalation is detected, thelimiter width can be expanded, and the temperature of the load 3 can befurther increased after the inhalation than before the temperature ofthe load 3 is decreased due to the inhalation. Thereby, it is possibleto recover the delay in heating after the temperature of the load 3 isrecovered and to optimize the heating of the load 3.

Also, in Example 5B, after the decrease in temperature is recovered, thecorrelation for limiter width change is returned to the state before thedecrease in temperature, so that it is possible to implement the stableaerosol generation.

Example 5C

In Example 5C, in the use phase, the control unit 8 stably controls thetemperature of the load 3 by the feedback control by reducing theinfluence of the feed-forward control of changing the limiter width whenthe limiter width is expanded to some extent.

FIG. 47 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 5C.

The control unit 8 detects the inhalation from an output value of asensor configured to detect a physical quantity that varies with theuser's inhalation, such as a flow rate sensor, a flow velocity sensorand a pressure sensor provided in the aerosol generation device 1.

In the use phase, the limiter change unit 13 expands gradually thelimiter width by the feed-forward control, based on the input parameter.When the inhalation is detected, the limiter change unit 13 expands theincrease width of the limiter width for the recovery of the temperatureof the load 3.

A limiter width control unit 22 provided in the control unit 8suppresses the expansion in the limiter width upon the inhalationdetection when the limiter width increases to some extent.

More specifically, the limiter width control unit 2 has a fourthrelation (hereinbelow, referred to as a compensation relation) where alimiter width and a compensation coefficient corresponding to thelimiter width are associated with each other, for example. Thecompensation coefficient indicates a degree of expanding the limiterwidth to recover the temperature upon the inhalation detection. In thecompensation relation, for example, the limiter width and thecompensation coefficient have an inverse correlation. That is, in thecompensation relation, for example, the smaller the limiter width is,the greater the compensation coefficient is, and the greater the limiterwidth is, the smaller the compensation coefficient is. The smaller thecompensation coefficient is, the increase width of the limiter widththat is changed upon the inhalation detection is further suppressed. Asa result, the greater the compensation coefficient is, the limiter widthis further sensitively expanded with respect to the inhalationdetection, and the smaller the compensation coefficient is, the limiterwidth expansion is further limited with respect to the inhalationdetection.

As an example, as shown in FIG. 47 , in the fourth relation, when thelimiter width increases to a threshold value or greater, thecorresponding compensation coefficient may be zero. As an example, asshown in FIG. 47 , in the fourth relation, the compensation coefficientmay have an upper limit.

In Example 5C, as the limiter width is expanded, the effect of therecovery from the decrease in temperature by the expansion in thelimiter width upon the inhalation detection is reduced, and the effectof the recovery from the decrease in temperature by the feedback controlupon the inhalation detection increases. More specifically, when thelimiter width is expanded, a possibility that the duty ratio output fromthe gain unit 12 will be the duty operation value increases. As anexample, the duty ratio that is output from the gain unit 12 depends onthe difference between the use phase end temperature and the measuredtemperature value. Therefore, when there is no influence of the limiterunit 14, the decrease in temperature is effectively resolved by thefeedback control. Thereby, it is possible to stably perform the control.

FIG. 48 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 5C In FIG. 48 ,it is determined whether to change the limiter width upon the inhalationdetection, based on whether the timer value t is smaller than athreshold value t_(thre3). However, it may also be determined whether tochange the limiter width upon the inhalation detection, based on atleast one of the measured temperature value and the puff profile,instead of the timer value t or together with the timer value t.

The processing from step S4801 to step S4803 is the same as theprocessing from step S4301 to step S4303 in FIG. 43 .

In step S4804, the limiter width control unit 22 determines whether thetimer value t is smaller than a threshold value t_(thre3) indicative ofa progressed state of the use phase.

When it is determined that the timer value t is not smaller than thethreshold value t_(thre3) (a determination result in step S4804 isnegative), the limiter width control unit 22 does not change thecorrelation for limiter width change, and the processing proceeds tostep S4807.

When it determined that the timer value t is smaller than the thresholdvalue t_(thre3), the limiter change unit 13 determines whetherinhalation is detected. In step S4805.

When it determined that inhalation is not detected (a determinationresult in step S4805 is negative), the processing proceeds to stepS4807.

When it determined that inhalation is detected, the limiter change unit13 changes the correlation for limiter width change that is used in thelimiter change unit 13, based on the timer value t, in step S4806, andthe processing proceeds to step S4807.

The processing from step S4807 to step S4810 is the same as theprocessing from step S4306 to step S4309 in FIG. 43 .

The operational effects of Example 5C described above are described.

When the use phase progresses, the limiter width is expanded and thelimitation on the magnitude of the duty operation value obtained by thelimiter unit 14 is relaxed. In this way, when the limiter width that isused in the limiter unit 14 is sufficiently expanded, the feedbackcontrol is likely to effectively function, so that it is possible torecover the decrease in temperature of the load 3 upon the inhalation bythe feedback control even though the limiter width is not expanded withthe inhalation. In this case, when the limiter width is expanded, thecontrol that is executed in the use phase may be rather complicated.

In Example 5C, in order to recover the decrease in temperature of theload 3 that occurs upon the inhalation, the degree of expanding thelimiter width with the inhalation is gradually reduced, so that it ispossible to secure the stability of the temperature of the load 3 byusing the feedback control with a large operating amount that can beoutput.

Example 5D

In Example 5D, control of recovering the decrease in temperature of theload 3 upon the inhalation detection by changing the gain of the gainunit 12 is described. Herein, the change of a gain includes changing again function, changing a value included in the gain function, and thelike, for example.

FIG. 49 is a control block diagram depicting an example of control thatis executed by the control unit 8 in accordance with Example 5D.

The gain change unit 17 provided in the control unit 8 in accordancewith Example 5D changes a gain that is used in the gain unit 12, whenthe inhalation is detected, for example. More specifically, when theinhalation is detected, the gain change unit 17 changes the gain of thegain unit 12, more specifically, increases the gain of the gain unit 12so as to obtain a larger duty ratio than when the inhalation is notdetected, based on a difference input from the differential unit 11.

Thereby, it is possible to recover the decrease in temperature of theload 3 upon the inhalation.

FIG. 50 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 5D.

The processing from step S5001 to step S5004 is the same as theprocessing from step S4301 to step S4304 in FIG. 43 .

When it is determined in step S5004 that the inhalation is not detected(a determination result is negative), the processing proceeds to stepS5006.

When it is determined in step S5004 that the inhalation is detected (adetermination result is affirmative), the gain change unit 17 changes acorrelation for gain change, which indicates a correlation between again and an input parameter, in step S5005, and the processing proceedsto step S5006.

In step S5006, the gain change unit 17 changes the gain of the gain unit12, based on the input parameter.

The processing from step S5007 to step S5009 is the same as theprocessing from step S4307 to step S4309 in FIG. 43 .

In Example 5D as described above, when the inhalation occurs, the gainof the gain unit 12 is changed to early recover the decrease intemperature of the load 3.

In the meantime, when the inhalation is detected, the control unit 8 maychange the use phase end temperature so as to increase the dutyoperation value that is obtained by the feedback control, instead of theincrease width of the limiter width that is used in the limiter unit 14or the gain of the gain unit 12 or together with the increase width ofthe limiter width or the gain. When the use phase end temperature isincreased, the difference that is output from the differential unit 11increases, so that the duty ratio output by the gain unit 12 increases.As a result, the duty operation value that is output by the feedbackcontrol can be increased.

Example 5E

In Example 5E, control of expanding the limiter width upon theinhalation detection and returning the limiter width to a value beforethe inhalation detection after the decrease in temperature of the load 3due to the inhalation is recovered is described.

FIG. 51 is a graph depicting an example of changes in the temperature ofthe load 3 and the limiter width in accordance with Example 5E. In thegraph, the horizontal axis indicates the timer value t, and the verticalaxis indicates the temperature of the load 3 and the limiter width.

As described above, the temperature of the load 3 is decreased upon theinhalation. When the inhalation is detected, the limiter change unit 13of the control unit 8 expands the limiter width, so that the controlunit 8 recovers the decreased temperature of the load 3.

The limiter change unit 13 detects the recovery of the temperature ofthe load 3 when the temperature of the load 3 returns to the statebefore the inhalation detection or when a predetermined time elapsessince the inhalation detection, for example. Then, the limiter changeunit 13 returns the limiter width to a value before the inhalation isdetected.

The control of Example 5E can also be applied to a case where thetemperature of the load 3 is kept constant.

FIG. 52 is a flowchart depicting an example of processing in the usephase by the control unit 8 in accordance with Example 5E.

The processing from step S5201 to step S5205 is the same as theprocessing from step S4601 to step S4605 in FIG. 46 .

In step S5204, when it is determined that the correlation for limiterwidth change has not been already changed (a determination result isnegative), the processing proceeds to step S5207.

When it is also determined in step S5205 that the decrease intemperature of the load 3 has not been recovered (a determination resultis negative), the processing proceeds to step S5207.

When it is determined in step S5205 that the decrease in temperature ofthe load 3 has been recovered (a determination result is affirmative),the limiter change unit 13 returns the limiter width to an originalstate in step S5206, and the processing proceeds to step S5207.

In step S5207, the control unit 8 determines whether the inhalation isdetected.

When it is determined that the inhalation is not detected (adetermination result in step S5207 is negative), the processing proceedsto step S5209.

When it is determined that the inhalation is detected (a determinationresult in step S5207 is affirmative), the limiter change unit 13 expandsthe limiter width that is used in the limiter unit 14, in step S5208,and proceeds to step S5209.

The processing from step S5209 to step S5212 is the same as theprocessing from step S4609 to step S4612 in FIG. 46 .

In Example 5E as described above, when the inhalation is detected, thetemperature of the load 3 can be recovered promptly and appropriately,and after the temperature of the load 3 is recovered, the limiter widththat is used in the limiter unit 14 can be again returned to the valuebefore the inhalation is detected. Thereby, the temperature of the load3 can be stabilized.

The above embodiments can be freely combined. The embodiments areexemplary and are not intended to limit the scope of the invention. Theembodiments can be implemented in other diverse forms, and can bediversely omitted, replaced and changed without departing from the gistof the invention. The embodiments and modifications thereof are includedin the claims and the equivalent scope thereof as well as the scope andgist of the invention.

What is claimed is:
 1. An aerosol generation device comprising: a loadconfigured to heat an aerosol generation article by using power that issupplied from a power source, the aerosol generation article comprisingan aerosol-forming substrate configured to hold or carry at least one ofan aerosol source and a flavor source; and circuitry configured tocontrol the power that is supplied from the power source to the load,wherein in a case of a use phase where a temperature of the load isequal to or higher than a value at which a predetermined amount or moreof aerosols is capable of being generated from the aerosol generationarticle, the circuitry is configured to acquire the temperature of theload and a degree of progress of the use phase, execute feedback controlso that the temperature of the load converges to a predeterminedtemperature, and increase a gain in the feedback control or an upperlimit value of the power that is supplied from the power source to theload, as the degree of progress progresses, in the feedback control. 2.The aerosol generation device according to claim 1, wherein thecircuitry is configured to increase the gain or the upper limit value asthe degree of progress progresses so that the temperature of the loaddoes not decrease from start of the use phase.
 3. The aerosol generationdevice according to claim 1, wherein an increase width of the gain orthe upper limit value with respect to a progressing width of the degreeof progress is constant.
 4. The aerosol generation device according toclaim 1, wherein the circuitry is configured to change an increase rateof the gain or the upper limit value with respect to a progressing widthof the degree of progress.
 5. The aerosol generation device according toclaim 4, wherein the circuitry is configured to increase the increaserate as the degree of progress progresses.
 6. The aerosol generationdevice according to claim 4, wherein the circuitry is configured toreduce the increase rate as the degree of progress progresses.
 7. Theaerosol generation device according to claim 1, wherein the circuitry isconfigured to: determine the gain or the upper limit value correspondingto the degree of progress based on a relation where the gain or theupper limit value increases as the degree of progress progresses; andchange the relation based on a time-series change in the degree ofprogress.
 8. The aerosol generation device according to claim 7, whereinthe circuitry is configured to change the relation so that the gain orthe upper limit value increases as the degree of progress progresses. 9.The aerosol generation device according to claim 7, wherein in a casethat the degree of progress is delayed in comparison with apredetermined degree of progress, the circuitry is configured to changethe relation so that an increase width of the gain or the upper limitvalue corresponding to a progressing width of the degree of progressincreases, and the degree of progress is the temperature of the load.10. The aerosol generation device according to claim 7, wherein in acase that the degree of progress is further progressed in comparisonwith a predetermined degree of progress, the circuitry is configured tochange the relation so that an increase width of the gain or the upperlimit value corresponding to a progressing width of the degree ofprogress decreases, and the degree of progress is the temperature of theload.
 11. The aerosol generation device according to claim 7, wherein ina case that the degree of progress is delayed in comparison with apredetermined degree of progress, the circuitry is configured to changethe relation so that an increase width of the gain or the upper limitvalue corresponding to a progressing width of the degree of progressdecreases, and the degree of progress is one of a number of times ofaerosol inhalation, an amount of aerosol inhalation, and an amount ofaerosol generation.
 12. The aerosol generation device according to claim7, wherein in a case that the degree of progress is further progressedin comparison with a predetermined degree of progress, the circuitry isconfigured to change the relation so that an increase width of the gainor the upper limit value corresponding with respect to a progressingwidth of the degree of progress increases, and the degree of progress isone of a number of times of aerosol inhalation, an amount of aerosolinhalation, and an amount of aerosol generation.
 13. The aerosolgeneration device according to claim 7, wherein the circuitry isconfigured to temporarily change the relation or to change a part of therelation.
 14. The aerosol generation device according to claim 7,wherein the circuitry is configured to change an entire part of therelation that is after the latest degree of progress acquired.
 15. Theaerosol generation device according to claim 7, wherein the circuitry isconfigured to: change a part of the relation that is after the latestdegree of progress acquired by the control unit; and set a relationbetween the degree of progress and the gain or the upper limit value atthe end of the use phase to be the same before and after the change ofthe relation.
 16. The aerosol generation device according to claim 1,wherein the predetermined temperature is a temperature of the load thatis necessary to generate aerosols from the aerosol source or theaerosol-forming substrate included in mounted aerosol generation articleand located in a position most distant from the load.
 17. The aerosolgeneration device according to claim 1, wherein the degree of progressis lapse time of the use phase, a number of times of aerosol inhalation,an amount of aerosol inhalation, an amount of aerosol generation or atemperature of the load.
 18. A control method of power that is suppliedfrom a power source to a load, the load being used to heat an aerosolgeneration article comprising an aerosol-forming substrate configured tohold or carry at least one of an aerosol source and a flavor source, thecontrol method comprising: starting supply of the power from the powersource to the load; in a case of a use phase where a temperature of theload is equal to or higher than a value at which a predetermined amountor more of aerosols is capable of being generated from the aerosolgeneration article, acquiring the temperature of the load and a degreeof progress of the use phase; executing feedback control so that thetemperature of the load converges to a predetermined temperature; andincreasing a gain in the feedback control or an upper limit value of thepower that is supplied from the power source to the load, as the degreeof progress progresses, in the feedback control.
 19. An aerosolgeneration device comprising: a load configured to heat an aerosolgeneration article by using power that is supplied from a power source,the aerosol generation article comprising an aerosol-forming substrateconfigured to hold or carry at least one of an aerosol source and aflavor source; and circuitry configured to acquire a temperature of theload; execute feedback control based on the temperature of the load; andcontrol the power that is supplied from the power source to the load,wherein the circuitry is configured to increase a gain in the feedbackcontrol or an upper limit value of the power that is supplied from thepower source to the load so that the temperature of the load graduallyapproaches from a first temperature, at which a predetermined amount ormore of aerosols is capable of being generated from the aerosol sourceor the aerosol-forming substrate included in the aerosol generationarticle and located in a position closest to the load, to a secondtemperature at which the predetermined amount or more of aerosols iscapable of being generated from the aerosol source or theaerosol-forming substrate included in the aerosol generation article andlocated in a position most distant from the load.
 20. Acomputer-readable non-transitory storage medium storing a program forcausing a computer to implement the control method according to claim18.